staging: brcm80211: remove unused parameter from data interface in fullmac

Remove redundant complete function pointer in send/recv buffer interface.

Reviewed-by: Arend van Spriel <arend@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>