[ROSE]: Fix routing table locking in rose_remove_neigh.

The locking rule for rose_remove_neigh() are that the caller needs to
hold rose_neigh_list_lock, so we better don't take it yet again in
rose_neigh_list_lock.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>