Fix unit test of ShareSnapshotNotFound
Fix unit test of ShareSnapshotNotFound

Unit test of ShareSnapshotNotFound isn't executed actually.
This patch fixes it.

Change-Id: I1210b10998ee9ab2c1642036747f06902239f0be

openstack/manila,scality/manila,openstack/manila,bswartz/manila,scality/manila,NetApp/manila,NetApp/manila,vponomaryov/manila,vponomaryov/manila,bswartz/manila