sunhme: Remove stop/wake TX queue calls in set-multicast-list handler.

Based upon a bug report by Alexander Beregalov and commentary
from Ben Hutchings.

These are totally unnecessary, in particular because this
driver's ->hard_start_xmit() handler takes the same driver
spinlock that the set-multicast-list handler uses.

Signed-off-by: David S. Miller <davem@davemloft.net>