glusterd/snapshot: delete temporary folder after snapshot create

snapshot create create temporary folders in /tmp location with
the name xfsmountXXXXXX. It should be cleaned up after snapshot
create

Change-Id: Idd0c480c1eee7f0fdeba92ae427510faac0f5234
BUG: 1111614
Signed-off-by: Rajesh Joseph <rjoseph@redhat.com>
Reviewed-on: http://review.gluster.org/8138
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Tested-by: Krishnan Parthasarathi <kparthas@redhat.com>