Don't fail chmod/chdir if a file doesn't exist
Don't fail chmod/chdir if a file doesn't exist

We don't use -f since we want to detect other errors (ro filesystem,
etc.)

Closes: #726203

agx/libvirt-debian,agx/libvirt-debian,agx/libvirt-debian,agx/libvirt-debian,agx/libvirt-debian