staging: brcm80211: remove parameter 'off' from _initvars_srom_pci()

The function is called once with parameter 'off' fixed to zero. This
parameter has been removed.

Reviewed-by: Alwin Beukers <alwin@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>