fixed unused variables/code warnings in scale box function BUG=libyuv:432 TESTED=local windows build with chromium_code =1 R=bcornell@google.com
fixed unused variables/code warnings in scale box function
BUG=libyuv:432
TESTED=local windows build with chromium_code =1
R=bcornell@google.com

Review URL: https://webrtc-codereview.appspot.com/49849004
eterrao/libyuv,happy-star/libyuv,weifud/libyuv,bluceldg/libyuv,muslim1977/libyuv,danilogr/libyuv,stephenyin/libyuv,foolab/libyuv,dreamcoder/libyuv,drybeans/libyuv,zijay0822/libyuv,skyofdwarf/libyuv,zpc930/libyuv,codyc/libyuv,sateeshyegireddi/libyuv,drybeans/libyuv,walletiger/libyuv,jrdeng/libyuv,Eikan/libyuv,Locnath/libyuv,ddpatel2606/libyuv,alfatraining/libyuv,xiongdaofu/libyuv,gavinljj/libyuv,Shamim1977/libyuv,binsys/libyuv,sepcity/libyuv,dreamcoder/libyuv,hushuitian/libyuv,sateeshyegireddi/libyuv,wmiller848/libyuv,muslim1977/libyuv,zj2089/libyuv,katepanping/libyuv,huangxueqin/libyuv,oiramario/libyuv,zpc930/libyuv,weifud/libyuv,zpc930/libyuv,platoon-code/libyuv,pecoco/libyuv,Eikan/libyuv,kiwifig/libyuv,gavinljj/libyuv,jeyluta/libyuv,ericma2014/libyuv,xiongdaofu/libyuv,alfatraining/libyuv,platoon-code/libyuv,jeyluta/libyuv,FAHADSUST/libyuv,dong83615/libyuv,koxiong/libyuv,jeyluta/libyuv,kpgalligan/libyuv,zhuolinho/libyuv,eterrao/libyuv,dong83615/libyuv,ericma2014/libyuv,Malek44/libyuv,leetaizhu/libyuv,weifud/libyuv,alfatraining/libyuv,buliaoyin/libyuv,jhanay/libyuv,muslim1977/libyuv,Shamim1977/libyuv,andriy-yermakov/libyuv,sepcity/libyuv,elkpi/libyuv,biotrump/libyuv,Padmassri/libyuv,biotrump/libyuv,swak/libyuv,huangxueqin/libyuv,xuruhao/libyuv,walletiger/libyuv,Miliox/libyuv,codyc/libyuv,jhanay/libyuv,buliaoyin/libyuv,andriy-yermakov/libyuv,cjr1983/libyuv,lcwyylcwyy/libyuv,ksophocleous/libyuv,platoon-code/libyuv,envyen/libyuv,Miliox/libyuv,hongqingquan/libyuv,lemoon/libyuv,wmiller848/libyuv,Shamim1977/libyuv,mayurAzoi/libyuv,KIHOSONG/libyuv,andriy-yermakov/libyuv,xiongdaofu/libyuv,zhuolinho/libyuv,xcl010/libyuv,leeslove/libyuv,mayurAzoi/libyuv,zothen/libyuv,leeslove/libyuv,codyc/libyuv,yosoymin/libyuv,mannuray/libyuv,Evgeniy-Odesskiy/libyuv,liuzhe02/libyuv,jrdeng/libyuv,leeslove/libyuv,zothen/libyuv,swak/libyuv,virneo/libyuv,changchang/libyuv,EdgarMora/libyuv,cjr1983/libyuv,mannuray/libyuv,Padmassri/libyuv,skyofdwarf/libyuv,changchang/libyuv,sepcity/libyuv,zephyroal/libyuv,KIHOSONG/libyuv,se7en3rd/libyuv,tectronics/libyuv,lemoon/libyuv,kiwifig/libyuv,heyfluke/libyuv,leetaizhu/libyuv,wanggenggz/libyuv,jrdeng/libyuv,walletiger/libyuv,xuruhao/libyuv,AshwanthSelvam/libyuv,zijay0822/libyuv,JuannyWang/libyuv,happy-star/libyuv,elkpi/libyuv,ddpatel2606/libyuv,danilogr/libyuv,patrickcusack/libyuv,Ariesnix/libyuv,sitoumbaz/libyuv,bluceldg/libyuv,pecoco/libyuv,zothen/libyuv,xcl010/libyuv,sateeshyegireddi/libyuv,ddpatel2606/libyuv,BigMing001/libyuv,FAHADSUST/libyuv,sigysmund/libyuv,KIHOSONG/libyuv,fjyihan/libyuv,nanguantong/libyuv,liuzhe02/libyuv,wanggenggz/libyuv,buliaoyin/libyuv,patrickcusack/libyuv,mayurAzoi/libyuv,eterrao/libyuv,lyx2014/libyuv,lcwyylcwyy/libyuv,lyx2014/libyuv,todostreaming/libyuv,se7en3rd/libyuv,envyen/libyuv,zhuolinho/libyuv,zephyroal/libyuv,drybeans/libyuv,changchang/libyuv,AshwanthSelvam/libyuv,polyzz/libyuv,oiramario/libyuv,lcwyylcwyy/libyuv,nanguantong/libyuv,binsys/libyuv,katepanping/libyuv,EdgarMora/libyuv,Locnath/libyuv,envyen/libyuv,cjr1983/libyuv,ericma2014/libyuv,fjyihan/libyuv,liuzhe02/libyuv,se7en3rd/libyuv,wow2006/libyuv,foolab/libyuv,skyofdwarf/libyuv,theunreplicated/libyuv,nanguantong/libyuv,happy-star/libyuv,sitoumbaz/libyuv,Eikan/libyuv,gavinljj/libyuv,wanggenggz/libyuv,hushuitian/libyuv,sigysmund/libyuv,Ariesnix/libyuv,huangxueqin/libyuv,zephyroal/libyuv,ksophocleous/libyuv,kiwifig/libyuv,alfatraining/libyuv,xcl010/libyuv,torodavit/libyuv,bluceldg/libyuv,tectronics/libyuv,Evgeniy-Odesskiy/libyuv,BigMing001/libyuv,Locnath/libyuv,danilogr/libyuv,zj2089/libyuv,BigMing001/libyuv,binsys/libyuv,biotrump/libyuv,zj2089/libyuv,jhanay/libyuv,stephenyin/libyuv,EdgarMora/libyuv,elkpi/libyuv,wmiller848/libyuv,polyzz/libyuv,polyzz/libyuv,sigysmund/libyuv,Ariesnix/libyuv,Malek44/libyuv,virneo/libyuv,swak/libyuv,todostreaming/libyuv,zijay0822/libyuv,theunreplicated/libyuv,torodavit/libyuv,stephenyin/libyuv,hongqingquan/libyuv,dong83615/libyuv,wow2006/libyuv,hongqingquan/libyuv,yosoymin/libyuv,virneo/libyuv,fjyihan/libyuv,theunreplicated/libyuv,Malek44/libyuv,tectronics/libyuv,katepanping/libyuv,gengchenglin/libyuv,kpgalligan/libyuv,patrickcusack/libyuv,xuruhao/libyuv,Padmassri/libyuv,lemoon/libyuv,dreamcoder/libyuv,hushuitian/libyuv,kpgalligan/libyuv,koxiong/libyuv,FAHADSUST/libyuv,torodavit/libyuv,JuannyWang/libyuv,mannuray/libyuv,heyfluke/libyuv,leetaizhu/libyuv,lyx2014/libyuv,Evgeniy-Odesskiy/libyuv,gengchenglin/libyuv,wow2006/libyuv,gengchenglin/libyuv,Miliox/libyuv,oiramario/libyuv,sitoumbaz/libyuv,pecoco/libyuv,AshwanthSelvam/libyuv,koxiong/libyuv,JuannyWang/libyuv,heyfluke/libyuv,ksophocleous/libyuv,yosoymin/libyuv,todostreaming/libyuv,foolab/libyuv