C Unit Test: Only perform lsm_fs_child_dependency_delete against sim plugin
C Unit Test: Only perform lsm_fs_child_dependency_delete against sim plugin

 * The current code of lsm_fs_child_dependency() in simulator C plugin
   is incorrect:
    1. It only check the existence of a file system.
    2. Always return 0(not depended).

 * Instead of fixing simulator C plugin[1], this patch restrict the
   lsm_fs_child_dependency_delete() test to simulator plugin only.

[1] Have plan to use sqlite for state storing like simulator python plugin do.

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

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