fs-lib: fix do_mount return code
fs-lib: fix do_mount return code

make exit path similar to netfs.sh do_mount

Resolves: rhbz#728086

Signed-off-by: Fabio M. Di Nitto <510df3d038b805d3c95a0d349043a42f16d04605@redhat.com>
Reviewed-by: Chris Feist <fa1b67118ccdbff4145f7b8177a82abf3f2bcd77@redhat.com>

asp24/resource-agents,stevenraspudic/resource-agents,asp24/resource-agents,asp24/resource-agents,stevenraspudic/resource-agents,stevenraspudic/resource-agents