[DLM] fix new_lockspace error exit [5/6]

Fix the error path when exiting new_lockspace().  It was kfree'ing the
lockspace struct at the end, but that's only valid if it exits before
kobject_register occured.  After kobject_register we have to let the
kobject do the freeing.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>