net: bcmgenet: synchronize use of bcmgenet_set_rx_mode()

commit 2dbe5f19 upstream.

The ndo_set_rx_mode function is synchronized with the
netif_addr_lock spinlock and BHs disabled. Since this
function is also invoked directly from the driver the
same synchronization should be applied.

Fixes: 72f96347

 ("net: bcmgenet: set Rx mode before starting netif")
Cc: stable@vger.kernel.org
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>