staging: fix build failure in bcm driver

While building latest Linus git, I hit the following:

    CC [M]  drivers/staging/bcm/Qos.o
  drivers/staging/bcm/Qos.c: In function ‘PruneQueue’:
  drivers/staging/bcm/Qos.c:367: error: ‘struct netdev_queue’ has no member named ‘tx_dropped’
  drivers/staging/bcm/Qos.c: In function ‘flush_all_queues’:
  drivers/staging/bcm/Qos.c:416: error: ‘struct netdev_queue’ has no member named ‘tx_dropped’
  make[5]: *** [drivers/staging/bcm/Qos.o] Error 1
  make[4]: *** [drivers/staging/bcm] Error 2
  make[3]: *** [drivers/staging] Error 2

As well as:

    CC [M]  drivers/staging/bcm/Transmit.o
  drivers/staging/bcm/Transmit.c: In function ‘SetupNextSend’:
  drivers/staging/bcm/Transmit.c:163: error: ‘struct netdev_queue’ has no member named ‘tx_bytes’
  drivers/staging/bcm/Transmit.c:164: error: ‘struct netdev_queue’ has no member named ‘tx_packets’
  make[2]: *** [drivers/staging/bcm/Transmit.o] Error 1

tx_dropped/tx_bytes_tx_packets were removed in commit 1ac9ad13.  This patch
converts bcm to use net_device_stats instead of netdev_queue.

Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>