vfs_unityed_media: remove handling of init_search_op

init_search_op is about to be removed from the VFS in
a following commit. In the meantime, removing it poses
no issue because he underlying impementation is a no-op.

Signed-off-by: Uri Simchoni <uri@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>