add missed defer to unlock
add missed defer to unlock

Signed-off-by: Alexander Morozov <2043cda4df124b840b98ee1c4307c199042efdf7@gmail.com>

vdemeester/docker,mahak/docker,konstruktoid/docker-upstream,jimjag/docker,yosifkit/docker,AkihiroSuda/docker,yosifkit/docker,flavio/docker,cpuguy83/docker,djs55/docker,thaJeztah/docker,konstruktoid/docker-upstream,Ramzec/docker,paralin/docker,Mokolea/docker,jimjag/docker,vdemeester/docker,gnailuy/docker,mahak/docker,vdemeester/docker,nawawi/docker,jameszhan/docker,thaJeztah/docker,nawawi/docker,cpuguy83/docker,cpuguy83/docker,Ramzec/docker,moul/docker,Ramzec/docker,mahak/docker,trebonian/docker,Mokolea/docker,moby/moby,cpuguy83/docker,nawawi/docker,jameszhan/docker,moul/docker,paralin/docker,docker/docker,yosifkit/docker,jimjag/docker,nawawi/docker,flavio/docker,moby/moby,bearstech/moby,trebonian/docker,djs55/docker,trebonian/docker,Mokolea/docker,thaJeztah/docker,nalind/docker,jthelin/docker,paralin/docker,bearstech/moby,docker/docker,mahak/docker,konstruktoid/docker-upstream,yosifkit/docker,jimjag/docker,jameszhan/docker,Mokolea/docker,moul/docker,bearstech/moby,AkihiroSuda/docker,djs55/docker,moby/moby,flavio/docker,AkihiroSuda/docker,docker/docker,trebonian/docker,moby/moby,jthelin/docker,gnailuy/docker,nalind/docker,paralin/docker,Ramzec/docker,thaJeztah/docker,nalind/docker,konstruktoid/docker-upstream,AkihiroSuda/docker,nalind/docker,gnailuy/docker,moul/docker,flavio/docker,bearstech/moby,gnailuy/docker