volume/local: call umount unconditionally
volume/local: call umount unconditionally

There is no need to parse mount table and iterate through the list of
mounts, and then call Unmount() which again parses the mount table and
iterates through the list of mounts.

It is totally OK to call Unmount() unconditionally.

Signed-off-by: Kir Kolyshkin <3a017b8ddb3f9cf3e4a59978b004111bdeb97f08@gmail.com>

ibuildthecloud/docker,nalind/docker,nawawi/docker,kolyshkin/docker,jlhawn/docker,cpuguy83/docker,pradipd/moby,yosifkit/docker,justincormack/docker,tophj-ibm/moby,pradipd/moby,tmp6154/docker,YuPengZTE/docker,yosifkit/docker,kojiromike/docker,mahak/docker,gnailuy/docker,tophj-ibm/docker,dmcgowan/docker,cpuguy83/docker,docker/docker,nawawi/docker,tophj-ibm/moby,tonistiigi/docker,rremer/moby,dmcgowan/docker,mikebrow/docker,unclejack/docker,johnstep/moby-moby,yongtang/docker,mikebrow/docker,ibuildthecloud/docker,laijs/docker,docker/docker,jameszhan/docker,dims/docker,maxamillion/docker,allencloud/docker,nawawi/docker,jlhawn/docker,vdemeester/docker,kolyshkin/docker,vdemeester/docker,jvanz/docker,paralin/docker,YuPengZTE/docker,kolyshkin/moby,jameszhan/docker,konstruktoid/docker-upstream,rancher/docker,scotttlin/docker,tophj-ibm/docker,laijs/moby,jimjag/docker,x1022as/docker,tmp6154/docker,yongtang/docker,johnstep/moby-moby,justincormack/docker,moul/docker,flavio/docker,tmp6154/docker,Ramzec/docker,KarthikNayak/docker,konstruktoid/docker-upstream,tonistiigi/docker,nalind/docker,thaJeztah/docker,crosbymichael/docker,crosbymichael/docker,paralin/docker,laijs/docker,Mokolea/docker,x1022as/docker,AkihiroSuda/docker,yosifkit/docker,kolyshkin/moby,dmcgowan/docker,trebonian/docker,AkihiroSuda/docker,jimjag/docker,rremer/moby,flavio/docker,AkihiroSuda/docker,estesp/docker,mikebrow/docker,trebonian/docker,rancher/docker,jimjag/docker,flavio/docker,scotttlin/docker,maxamillion/docker,ibuildthecloud/docker,nawawi/docker,Ramzec/docker,AkihiroSuda/docker,bearstech/moby,ibuildthecloud/docker,dims/docker,konstruktoid/docker-upstream,yosifkit/docker,laijs/moby,jameszhan/docker,laijs/moby,estesp/docker,mahak/docker,johnstep/moby-moby,moby/moby,crosbymichael/docker,jwhonce/docker,flavio/docker,jwhonce/docker,gnailuy/docker,docker/docker,cpuguy83/docker,unclejack/docker,gnailuy/docker,konstruktoid/docker-1,mahak/docker,Mokolea/docker,trebonian/docker,thaJeztah/docker,djs55/docker,allencloud/docker,SvenDowideit/docker,vdemeester/docker,KarthikNayak/docker,scotttlin/docker,jvanz/docker,cpuguy83/docker,maxamillion/docker,duglin/docker,SvenDowideit/docker,konstruktoid/docker-1,estesp/docker,nalind/docker,Ramzec/docker,Ramzec/docker,kolyshkin/moby,dims/docker,ibuildthecloud/docker,pradipd/moby,jvanz/docker,laijs/docker,allencloud/docker,jimjag/docker,moby/moby,moul/docker,djs55/docker,unclejack/docker,tonistiigi/docker,kojiromike/docker,kojiromike/docker,gnailuy/docker,paralin/docker,duglin/docker,duglin/docker,trebonian/docker,djs55/docker,thaJeztah/docker,konstruktoid/docker-1,moby/moby,thaJeztah/docker,tophj-ibm/moby,moul/docker,moul/docker,jlhawn/docker,Mokolea/docker,rremer/moby,moby/moby,bearstech/moby,tophj-ibm/docker,nalind/docker,jwhonce/docker,Mokolea/docker,rancher/docker,yongtang/docker,jthelin/docker,mahak/docker,bearstech/moby,justincormack/docker,SvenDowideit/docker,paralin/docker,bearstech/moby,konstruktoid/docker-upstream,x1022as/docker,jthelin/docker,KarthikNayak/docker,YuPengZTE/docker