brcmfmac: remove fifo bitfield from brcmf_skbuff_cb::if_flags

brcmfmac: remove fifo bitfield from brcmf_skbuff_cb::if_flags

The brcmf_skbuff_cb structure contain if_flags and htod fields. Both
have a bitfield defined to hold the fifo number. With a small code
change we get rid of the fifo bitfield in if_flags.

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