brcmfmac: Return correct error on netdev xmit.

brcmfmac: Return correct error on netdev xmit.

Netdev xmit routine brcfm_netdev_start_xmit was defined
incorrectly and used wrong return codes. Always eat the
packet and return ok. Remove drvr_up check since it is not
relevant.

Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>