libertas: fix return from lbs_update_channel()

If we return the channel number in a 'ret' variable where anything
non-zero is later interpreted as an error, that isn't nice. It breaks
WPA, for a start. OLPC trac #5485
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/assoc.c

@@ -167,13 +167,14 @@ int lbs_update_channel(struct lbs_private *priv)
 {
 	int ret;
 
-	/* the channel in f/w could be out of sync, get the current channel */
+	/* the channel in f/w could be out of sync; get the current channel */
 	lbs_deb_enter(LBS_DEB_ASSOC);
 
 	ret = lbs_get_channel(priv);
-	if (ret > 0)
-		priv->curbssparams.channel = (u8) ret;
-
+	if (ret > 0) {
+		priv->curbssparams.channel = ret;
+		ret = 0;
+	}
 	lbs_deb_leave_args(LBS_DEB_ASSOC, "ret %d", ret);
 	return ret;
 }
@@ -197,8 +198,9 @@ static int assoc_helper_channel(struct lbs_private *priv,
 	lbs_deb_enter(LBS_DEB_ASSOC);
 
 	ret = lbs_update_channel(priv);
-	if (ret < 0) {
+	if (ret) {
 		lbs_deb_assoc("ASSOC: channel: error getting channel.\n");
+		goto done;
 	}
 
 	if (assoc_req->channel == priv->curbssparams.channel)
@@ -222,8 +224,10 @@ static int assoc_helper_channel(struct lbs_private *priv,
 	 * it since the firmware is supposed to return the new channel, but
 	 * whatever... */
 	ret = lbs_update_channel(priv);
-	if (ret < 0)
+	if (ret) {
 		lbs_deb_assoc("ASSOC: channel: error getting channel.\n");
+		goto done;
+	}
 
 	if (assoc_req->channel != priv->curbssparams.channel) {
 		lbs_deb_assoc("ASSOC: channel: failed to update channel to %d\n",