object-storage: cleanup err handling in Glusterfs.

Change-Id: I4fa1a7b9214c6897459a99bedde80e84eb2b9cbc
BUG: 904370
Signed-off-by: Mohammed Junaid <junaid@redhat.com>
Reviewed-on: http://review.gluster.org/4788
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>