dlm: fixed memory leaks after failed ls_remove_names allocation

commit b982896cdb6e6a6b89d86dfb39df489d9df51e14 upstream.

If allocation fails on last elements of array need to free already
allocated elements.

v2: just move existing out_rsbtbl label to right place

Fixes 789924ba635f ("dlm: fix race between remove and lookup")
Cc: stable@kernel.org # 3.6

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>