brcmfmac: Fix grammar issue in error message

Fix grammar issue in error message about ISO3166.
Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c

@@ -6778,7 +6778,7 @@ static void brcmf_cfg80211_reg_notifier(struct wiphy *wiphy,
 	/* ignore non-ISO3166 country codes */
 	for (i = 0; i < sizeof(req->alpha2); i++)
 		if (req->alpha2[i] < 'A' || req->alpha2[i] > 'Z') {
-			brcmf_err("not a ISO3166 code (0x%02x 0x%02x)\n",
+			brcmf_err("not an ISO3166 code (0x%02x 0x%02x)\n",
 				  req->alpha2[0], req->alpha2[1]);
 			return;
 		}