staging: brcm80211: fix checkpatch issue introduced in dhd_sdio.c

Patch "[2349e278] move utility functions into new module" introduced
a checkpatch warning which is resolved with this patch.

Cc: devel@linuxdriverproject.org
Reviewed-by: Henry Ptasinski <henryp@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Brett Rudley <brudley@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>