Fix leak of watchMiss goroutine
Fix leak of watchMiss goroutine

The netlink socket that was used to monitor the L2
miss was never being closed. The watchMiss goroutine
spawned was never returning. This was causing goroutine
leak in case of createNetwork/destroyNetwork

Signed-off-by: Flavio Crisciani <59eae1aa696b1b39cd87a38bdba3f0b2630647f9@docker.com>

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