Fix race in call.c
Fix race in call.c

makdharma/grpc,rjshade/grpc,msmania/grpc,mehrdada/grpc,daniel-j-born/grpc,carl-mastrangelo/grpc,grpc/grpc,kskalski/grpc,ejona86/grpc,geffzhang/grpc,ctiller/grpc,matt-kwong/grpc,ctiller/grpc,firebase/grpc,PeterFaiman/ruby-grpc-minimal,hstefan/grpc,adelez/grpc,carl-mastrangelo/grpc,daniel-j-born/grpc,vjpai/grpc,carl-mastrangelo/grpc,hstefan/grpc,carl-mastrangelo/grpc,sreecha/grpc,thinkerou/grpc,grpc/grpc,hstefan/grpc,quizlet/grpc,vsco/grpc,kpayson64/grpc,ncteisen/grpc,muxi/grpc,dklempner/grpc,rjshade/grpc,baylabs/grpc,simonkuang/grpc,ipylypiv/grpc,dgquintas/grpc,nicolasnoble/grpc,donnadionne/grpc,fuchsia-mirror/third_party-grpc,deepaklukose/grpc,mehrdada/grpc,chrisdunelm/grpc,Crevil/grpc,nicolasnoble/grpc,kriswuollett/grpc,nicolasnoble/grpc,kskalski/grpc,msmania/grpc,jboeuf/grpc,kriswuollett/grpc,jboeuf/grpc,pszemus/grpc,adelez/grpc,simonkuang/grpc,grani/grpc,deepaklukose/grpc,baylabs/grpc,wcevans/grpc,makdharma/grpc,kriswuollett/grpc,yang-g/grpc,daniel-j-born/grpc,royalharsh/grpc,zhimingxie/grpc,ctiller/grpc,baylabs/grpc,donnadionne/grpc,simonkuang/grpc,kskalski/grpc,baylabs/grpc,makdharma/grpc,dklempner/grpc,ctiller/grpc,kpayson64/grpc,fuchsia-mirror/third_party-grpc,stanley-cheung/grpc,quizlet/grpc,rjshade/grpc,muxi/grpc,rjshade/grpc,jboeuf/grpc,kumaralokgithub/grpc,pszemus/grpc,yang-g/grpc,sreecha/grpc,wcevans/grpc,jtattermusch/grpc,donnadionne/grpc,vjpai/grpc,muxi/grpc,vsco/grpc,MakMukhi/grpc,baylabs/grpc,stanley-cheung/grpc,murgatroid99/grpc,baylabs/grpc,yongni/grpc,chrisdunelm/grpc,quizlet/grpc,msmania/grpc,nicolasnoble/grpc,matt-kwong/grpc,philcleveland/grpc,ctiller/grpc,MakMukhi/grpc,Crevil/grpc,grpc/grpc,grani/grpc,hstefan/grpc,philcleveland/grpc,grpc/grpc,ncteisen/grpc,firebase/grpc,chrisdunelm/grpc,dklempner/grpc,donnadionne/grpc,mehrdada/grpc,ipylypiv/grpc,donnadionne/grpc,7anner/grpc,dklempner/grpc,Vizerai/grpc,MakMukhi/grpc,ncteisen/grpc,mehrdada/grpc,pszemus/grpc,ncteisen/grpc,mehrdada/grpc,kumaralokgithub/grpc,a11r/grpc,firebase/grpc,thinkerou/grpc,zhimingxie/grpc,pszemus/grpc,dklempner/grpc,Crevil/grpc,quizlet/grpc,makdharma/grpc,philcleveland/grpc,simonkuang/grpc,msmania/grpc,adelez/grpc,ncteisen/grpc,PeterFaiman/ruby-grpc-minimal,apolcyn/grpc,fuchsia-mirror/third_party-grpc,murgatroid99/grpc,sreecha/grpc,deepaklukose/grpc,pszemus/grpc,sreecha/grpc,jboeuf/grpc,pszemus/grpc,kpayson64/grpc,ejona86/grpc,yongni/grpc,msmania/grpc,grpc/grpc,ctiller/grpc,thinkerou/grpc,muxi/grpc,stanley-cheung/grpc,vsco/grpc,thinkerou/grpc,stanley-cheung/grpc,geffzhang/grpc,philcleveland/grpc,fuchsia-mirror/third_party-grpc,Vizerai/grpc,7anner/grpc,a11r/grpc,matt-kwong/grpc,chrisdunelm/grpc,kskalski/grpc,simonkuang/grpc,7anner/grpc,Vizerai/grpc,kskalski/grpc,murgatroid99/grpc,deepaklukose/grpc,philcleveland/grpc,ctiller/grpc,muxi/grpc,stanley-cheung/grpc,dklempner/grpc,carl-mastrangelo/grpc,ejona86/grpc,fuchsia-mirror/third_party-grpc,matt-kwong/grpc,daniel-j-born/grpc,firebase/grpc,donnadionne/grpc,carl-mastrangelo/grpc,pszemus/grpc,chrisdunelm/grpc,geffzhang/grpc,ejona86/grpc,7anner/grpc,muxi/grpc,kumaralokgithub/grpc,ejona86/grpc,yongni/grpc,adelez/grpc,vsco/grpc,PeterFaiman/ruby-grpc-minimal,yongni/grpc,fuchsia-mirror/third_party-grpc,simonkuang/grpc,jtattermusch/grpc,firebase/grpc,muxi/grpc,wcevans/grpc,dgquintas/grpc,PeterFaiman/ruby-grpc-minimal,kskalski/grpc,Crevil/grpc,wcevans/grpc,kpayson64/grpc,dklempner/grpc,adelez/grpc,ejona86/grpc,vsco/grpc,7anner/grpc,philcleveland/grpc,philcleveland/grpc,kpayson64/grpc,Vizerai/grpc,Crevil/grpc,kumaralokgithub/grpc,vjpai/grpc,simonkuang/grpc,hstefan/grpc,firebase/grpc,Vizerai/grpc,quizlet/grpc,kpayson64/grpc,yang-g/grpc,daniel-j-born/grpc,ipylypiv/grpc,vjpai/grpc,grani/grpc,pszemus/grpc,carl-mastrangelo/grpc,PeterFaiman/ruby-grpc-minimal,msmania/grpc,MakMukhi/grpc,muxi/grpc,7anner/grpc,dgquintas/grpc,adelez/grpc,grani/grpc,fuchsia-mirror/third_party-grpc,ejona86/grpc,mehrdada/grpc,jtattermusch/grpc,nicolasnoble/grpc,ejona86/grpc,yang-g/grpc,pszemus/grpc,makdharma/grpc,stanley-cheung/grpc,jtattermusch/grpc,daniel-j-born/grpc,ejona86/grpc,mehrdada/grpc,nicolasnoble/grpc,adelez/grpc,murgatroid99/grpc,mehrdada/grpc,deepaklukose/grpc,royalharsh/grpc,royalharsh/grpc,ipylypiv/grpc,PeterFaiman/ruby-grpc-minimal,muxi/grpc,chrisdunelm/grpc,vjpai/grpc,baylabs/grpc,ncteisen/grpc,MakMukhi/grpc,makdharma/grpc,vsco/grpc,mehrdada/grpc,donnadionne/grpc,apolcyn/grpc,royalharsh/grpc,thinkerou/grpc,yongni/grpc,a11r/grpc,vjpai/grpc,grpc/grpc,simonkuang/grpc,zhimingxie/grpc,7anner/grpc,jtattermusch/grpc,dgquintas/grpc,sreecha/grpc,PeterFaiman/ruby-grpc-minimal,apolcyn/grpc,jtattermusch/grpc,kpayson64/grpc,philcleveland/grpc,msmania/grpc,ncteisen/grpc,vjpai/grpc,rjshade/grpc,firebase/grpc,yongni/grpc,murgatroid99/grpc,royalharsh/grpc,sreecha/grpc,ctiller/grpc,dgquintas/grpc,dgquintas/grpc,MakMukhi/grpc,thinkerou/grpc,baylabs/grpc,thinkerou/grpc,thinkerou/grpc,donnadionne/grpc,daniel-j-born/grpc,pszemus/grpc,donnadionne/grpc,daniel-j-born/grpc,pszemus/grpc,zhimingxie/grpc,jtattermusch/grpc,stanley-cheung/grpc,kskalski/grpc,matt-kwong/grpc,Crevil/grpc,daniel-j-born/grpc,ipylypiv/grpc,fuchsia-mirror/third_party-grpc,quizlet/grpc,Vizerai/grpc,ipylypiv/grpc,vsco/grpc,a11r/grpc,apolcyn/grpc,Crevil/grpc,apolcyn/grpc,a11r/grpc,a11r/grpc,murgatroid99/grpc,msmania/grpc,makdharma/grpc,MakMukhi/grpc,dklempner/grpc,murgatroid99/grpc,ejona86/grpc,ncteisen/grpc,kumaralokgithub/grpc,firebase/grpc,simonkuang/grpc,ctiller/grpc,geffzhang/grpc,dgquintas/grpc,grani/grpc,a11r/grpc,matt-kwong/grpc,ncteisen/grpc,mehrdada/grpc,vsco/grpc,donnadionne/grpc,chrisdunelm/grpc,makdharma/grpc,geffzhang/grpc,carl-mastrangelo/grpc,carl-mastrangelo/grpc,vjpai/grpc,thinkerou/grpc,muxi/grpc,dgquintas/grpc,geffzhang/grpc,baylabs/grpc,carl-mastrangelo/grpc,matt-kwong/grpc,vjpai/grpc,deepaklukose/grpc,ctiller/grpc,yongni/grpc,sreecha/grpc,kskalski/grpc,fuchsia-mirror/third_party-grpc,jtattermusch/grpc,dklempner/grpc,Vizerai/grpc,ipylypiv/grpc,a11r/grpc,kpayson64/grpc,jtattermusch/grpc,hstefan/grpc,nicolasnoble/grpc,jboeuf/grpc,sreecha/grpc,fuchsia-mirror/third_party-grpc,royalharsh/grpc,grpc/grpc,kriswuollett/grpc,kumaralokgithub/grpc,adelez/grpc,kpayson64/grpc,murgatroid99/grpc,rjshade/grpc,vsco/grpc,grpc/grpc,deepaklukose/grpc,geffzhang/grpc,wcevans/grpc,ctiller/grpc,jboeuf/grpc,Vizerai/grpc,dgquintas/grpc,wcevans/grpc,grani/grpc,grpc/grpc,jboeuf/grpc,a11r/grpc,jtattermusch/grpc,grani/grpc,carl-mastrangelo/grpc,apolcyn/grpc,PeterFaiman/ruby-grpc-minimal,rjshade/grpc,carl-mastrangelo/grpc,sreecha/grpc,jtattermusch/grpc,thinkerou/grpc,wcevans/grpc,yang-g/grpc,geffzhang/grpc,donnadionne/grpc,apolcyn/grpc,grani/grpc,rjshade/grpc,jboeuf/grpc,jboeuf/grpc,ipylypiv/grpc,zhimingxie/grpc,matt-kwong/grpc,Vizerai/grpc,kriswuollett/grpc,royalharsh/grpc,vjpai/grpc,chrisdunelm/grpc,thinkerou/grpc,kumaralokgithub/grpc,zhimingxie/grpc,nicolasnoble/grpc,grpc/grpc,yongni/grpc,firebase/grpc,sreecha/grpc,geffzhang/grpc,philcleveland/grpc,yang-g/grpc,royalharsh/grpc,quizlet/grpc,msmania/grpc,thinkerou/grpc,kriswuollett/grpc,7anner/grpc,donnadionne/grpc,wcevans/grpc,deepaklukose/grpc,kriswuollett/grpc,vjpai/grpc,yang-g/grpc,quizlet/grpc,ctiller/grpc,7anner/grpc,Vizerai/grpc,sreecha/grpc,matt-kwong/grpc,royalharsh/grpc,nicolasnoble/grpc,stanley-cheung/grpc,ncteisen/grpc,zhimingxie/grpc,zhimingxie/grpc,jtattermusch/grpc,hstefan/grpc,sreecha/grpc,ncteisen/grpc,firebase/grpc,kumaralokgithub/grpc,murgatroid99/grpc,kriswuollett/grpc,rjshade/grpc,PeterFaiman/ruby-grpc-minimal,muxi/grpc,kumaralokgithub/grpc,vjpai/grpc,Crevil/grpc,chrisdunelm/grpc,mehrdada/grpc,grpc/grpc,quizlet/grpc,firebase/grpc,yongni/grpc,stanley-cheung/grpc,muxi/grpc,adelez/grpc,Crevil/grpc,makdharma/grpc,nicolasnoble/grpc,Vizerai/grpc,ncteisen/grpc,deepaklukose/grpc,MakMukhi/grpc,hstefan/grpc,ipylypiv/grpc,nicolasnoble/grpc,ejona86/grpc,chrisdunelm/grpc,chrisdunelm/grpc,jboeuf/grpc,apolcyn/grpc,hstefan/grpc,wcevans/grpc,pszemus/grpc,PeterFaiman/ruby-grpc-minimal,stanley-cheung/grpc,jboeuf/grpc,nicolasnoble/grpc,kpayson64/grpc,grpc/grpc,stanley-cheung/grpc,mehrdada/grpc,MakMukhi/grpc,firebase/grpc,zhimingxie/grpc,yang-g/grpc,grani/grpc,ejona86/grpc,kriswuollett/grpc,yang-g/grpc,dgquintas/grpc,murgatroid99/grpc,jboeuf/grpc,kskalski/grpc,dgquintas/grpc,stanley-cheung/grpc,kpayson64/grpc,apolcyn/grpc