pkg/term: use IoctlGetWinsize/IoctlSetWinsize from golang.org/x/sys/unix
pkg/term: use IoctlGetWinsize/IoctlSetWinsize from golang.org/x/sys/unix

Use unix.IoctlGetWinsize and unix.IoctlSetWinsize instead of manually
reimplementing them.

Signed-off-by: Tobias Klauser <9249c549618448e4c699e8032ba6c7f0d7fd4b7f@distanz.ch>

crosbymichael/docker,yummypeng/docker,rhatdan/docker,estesp/docker,raja-sami-10p/moby,justincormack/docker,ripcurld0/moby,tklauser/docker,pradipd/moby,thaJeztah/docker,yummypeng/docker,yongtang/docker,YuPengZTE/docker,gnailuy/docker,Mokolea/docker,jwhonce/docker,djs55/docker,bearstech/moby,KarthikNayak/docker,x1022as/docker,konstruktoid/docker-upstream,tonistiigi/docker,yosifkit/docker,kolyshkin/moby,konstruktoid/docker-upstream,nalind/docker,rancher/docker,miminar/docker,tophj-ibm/docker,dsheets/moby,moul/docker,dccurtis/docker,noironetworks/docker,paralin/docker,maxamillion/docker,gnailuy/docker,mixja/docker,SvenDowideit/docker,allencloud/docker,Ramzec/docker,YuPengZTE/docker,mahak/docker,kolyshkin/docker,nawawi/docker,rhatdan/docker,shishir-a412ed/docker,dims/docker,trebonian/docker,tmp6154/docker,tklauser/docker,ibuildthecloud/docker,trebonian/docker,pradipd/moby,KingEmet/docker,jvanz/docker,SvenDowideit/docker,mixja/docker,maxamillion/docker,tklauser/docker,raja-sami-10p/moby,jwhonce/docker,johnstep/moby-moby,laijs/docker,pramodhkp/moby,jthelin/docker,flavio/docker,gnailuy/docker,konstruktoid/docker-upstream,cpuguy83/docker,rhatdan/docker,cyphar/docker,sterchelen/docker,moby/moby,miminar/docker,dsheets/moby,laijs/moby,crosbymichael/docker,jimjag/docker,moby/moby,konstruktoid/docker-1,dsheets/moby,jimjag/docker,nalind/docker,nawawi/docker,scotttlin/docker,ibuildthecloud/docker,jimjag/docker,tonistiigi/docker,thaJeztah/docker,jvanz/docker,madhanrm/docker,duglin/docker,jwhonce/docker,moul/docker,paralin/docker,ripcurld0/moby,jameszhan/docker,danyalKhaliq10p/moby,KingEmet/docker,jlhawn/docker,nawawi/docker,moby/moby,mahak/docker,danyalKhaliq10p/moby,kojiromike/docker,kolyshkin/moby,tophj-ibm/moby,danyalKhaliq10p/moby,mahak/docker,yongtang/docker,dccurtis/docker,Mokolea/docker,docker/docker,flavio/docker,trebonian/docker,Mokolea/docker,tophj-ibm/docker,rremer/moby,konstruktoid/docker-1,vdemeester/docker,kolyshkin/docker,tonistiigi/docker,srust/docker,noironetworks/docker,sterchelen/docker,dims/docker,AkihiroSuda/docker,crosbymichael/docker,vdemeester/docker,docker/docker,scotttlin/docker,pramodhkp/moby,ndeloof/docker,docker/docker,PatrickLang/moby,jthelin/docker,unclejack/docker,duglin/docker,srust/docker,laijs/docker,paralin/docker,moul/docker,kojiromike/docker,whuwxl/docker,kolyshkin/moby,allencloud/docker,Mokolea/docker,yummypeng/docker,rremer/moby,tophj-ibm/moby,scotttlin/docker,justincormack/docker,tophj-ibm/docker,yongtang/docker,fcrisciani/docker,rremer/moby,allencloud/docker,rancher/docker,estesp/docker,jlhawn/docker,whuwxl/docker,paralin/docker,AkihiroSuda/docker,ndeloof/docker,jvanz/docker,thaJeztah/docker,dims/docker,johnstep/moby-moby,jimjag/docker,mixja/docker,rancher/docker,estesp/docker,cyphar/docker,konstruktoid/docker-upstream,jlhawn/docker,shishir-a412ed/docker,gnailuy/docker,YuPengZTE/docker,ibuildthecloud/docker,mikebrow/docker,ripcurld0/moby,yosifkit/docker,moul/docker,KarthikNayak/docker,Ramzec/docker,trebonian/docker,miminar/docker,pramodhkp/moby,yosifkit/docker,fcrisciani/docker,Ramzec/docker,bearstech/moby,AkihiroSuda/docker,fcrisciani/docker,cpuguy83/docker,unclejack/docker,vdemeester/docker,ibuildthecloud/docker,nawawi/docker,ibuildthecloud/docker,maxamillion/docker,konstruktoid/docker-1,laijs/docker,thaJeztah/docker,duglin/docker,mikebrow/docker,bearstech/moby,cyphar/docker,sterchelen/docker,KingEmet/docker,tmp6154/docker,ndeloof/docker,cpuguy83/docker,srust/docker,tmp6154/docker,noironetworks/docker,cpuguy83/docker,AkihiroSuda/docker,madhanrm/docker,justincormack/docker,nalind/docker,x1022as/docker,Ramzec/docker,moby/moby,madhanrm/docker,laijs/moby,yosifkit/docker,KarthikNayak/docker,dmcgowan/docker,PatrickLang/moby,pradipd/moby,mikebrow/docker,nalind/docker,PatrickLang/moby,dmcgowan/docker,djs55/docker,bearstech/moby,unclejack/docker,flavio/docker,x1022as/docker,shishir-a412ed/docker,djs55/docker,kojiromike/docker,laijs/moby,mahak/docker,jameszhan/docker,dmcgowan/docker,whuwxl/docker,dccurtis/docker,johnstep/moby-moby,tophj-ibm/moby,jameszhan/docker,raja-sami-10p/moby,flavio/docker,SvenDowideit/docker