glusterd: fix unix domain notify fn

... and unlink the 'right' socket file

Change-Id: Id12ee8c622914555b7933104e13b43b3b31b5d19
BUG: 1176770
Signed-off-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-on: http://review.gluster.org/9315
Reviewed-by: Kaushal M <kaushal@redhat.com>
Tested-by: Kaushal M <kaushal@redhat.com>