Fix "unmount" bash completion
Fix "unmount" bash completion

Fix the infinitely self-recursing, but immediately replaced, version of
the "umount" completion function with the missing "unmount" completion
function.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

Closes: #143
Approved by: rhatdan

TomSweeneyRedHat/buildah,TomSweeneyRedHat/buildah,ipbabble/buildah,nalind/buildah,rhatdan/buildah,nalind/buildah-1,rhatdan/buildah,nalind/buildah,projectatomic/buildah,ipbabble/buildah,TomSweeneyRedHat/buildah,nalind/buildah-1,rhatdan/buildah,projectatomic/buildah,nalind/buildah-1,projectatomic/buildah