brcm80211: smac: do not use US as fallback regulatory hint

The brcmsmac driver provides the country code from sprom as a regulatory
hint to cfg80211. When brcmsmac does not find a country code entry in
the sprom it passes 'US' as regulatory hint. Better approach is to rely
on the world regulatory domain in cfg80211/crda.
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Brett Rudley <brudley@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c

@@ -1069,11 +1069,7 @@ static struct brcms_info *brcms_attach(struct bcma_device *pdev)
 		wiphy_err(wl->wiphy, "%s: ieee80211_register_hw failed, status"
 			  "%d\n", __func__, err);
 
-	if (wl->pub->srom_ccode[0])
-		err = brcms_set_hint(wl, wl->pub->srom_ccode);
-	else
-		err = brcms_set_hint(wl, "US");
-	if (err)
+	if (wl->pub->srom_ccode[0] && brcms_set_hint(wl, wl->pub->srom_ccode))
 		wiphy_err(wl->wiphy, "%s: regulatory_hint failed, status %d\n",
 			  __func__, err);