Simulator C Plugin: Raise LSM_ERR_NO_STATE_CHANGE when not masked.
Simulator C Plugin: Raise LSM_ERR_NO_STATE_CHANGE when not masked.

 * Raise LSM_ERR_NO_STATE_CHANGE when volume is not masked to requested
   access group on volume_unmask().

Signed-off-by: Gris Ge <e24f3acbe39bf94f92e8af3c48f8852106ad5ad7@redhat.com>

jumitche/libstoragemgmt,lazy404/libstoragemgmt,jumitche/libstoragemgmt,HP-Scale-out-Storage/libstoragemgmt,tasleson/libstoragemgmt,libstorage/libstoragemgmt,libstorage/libstoragemgmt,joehandzik/libstoragemgmt,tasleson/libstoragemgmt,tasleson/libstoragemgmt,joehandzik/libstoragemgmt,cathay4t/libstoragemgmt,cathay4t/libstoragemgmt,jumitche/libstoragemgmt,tasleson/libstoragemgmt,libstorage/libstoragemgmt,HP-Scale-out-Storage/libstoragemgmt,HP-Scale-out-Storage/libstoragemgmt,cathay4t/libstoragemgmt,lazy404/libstoragemgmt,joehandzik/libstoragemgmt,HP-Scale-out-Storage/libstoragemgmt,libstorage/libstoragemgmt,cathay4t/libstoragemgmt,libstorage/libstoragemgmt,lazy404/libstoragemgmt,jumitche/libstoragemgmt,tasleson/libstoragemgmt,joehandzik/libstoragemgmt,lazy404/libstoragemgmt,jumitche/libstoragemgmt,cathay4t/libstoragemgmt