mac80211: fix an oops in ieee80211_scan_state_set_channel

Fix an oops in ieee80211_scan_state_set_channel which was triggered
if the last scanned channel was skipped (for example due to regulatory
restrictions) by returning to the decision state after each skipped
channel.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/scan.c

@@ -605,8 +605,11 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 	/* advance state machine to next channel/band */
 	local->scan_channel_idx++;
 
-	if (skip)
+	if (skip) {
+		/* if we skip this channel return to the decision state */
+		local->next_scan_state = SCAN_DECISION;
 		return;
+	}
 
 	/*
 	 * Probe delay is used to update the NAV, cf. 11.1.3.2.2