mac80211: fix ibss scanning

Do not scan on no-IBSS and disabled channels in IBSS mode. Doing this
can trigger Microcode errors on iwlwifi and iwlegacy drivers.

Also rename ieee80211_request_internal_scan() function since it is only
used in IBSS mode and simplify calling it from ieee80211_sta_find_ibss().

This patch should address:
https://bugzilla.redhat.com/show_bug.cgi?id=883414
https://bugzilla.kernel.org/show_bug.cgi?id=49411

Reported-by: Jesse Kahtava <jesse_kahtava@f-m.fm>
Reported-by: Mikko Rapeli  <mikko.rapeli@iki.fi>
Cc: stable@vger.kernel.org
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 8881fc7..6b7644e 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -703,8 +703,8 @@
 	sdata_info(sdata,
 		   "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
 
-	ieee80211_request_internal_scan(sdata,
-			ifibss->ssid, ifibss->ssid_len, NULL);
+	ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
+				    NULL);
 }
 
 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
@@ -802,9 +802,8 @@
 					IEEE80211_SCAN_INTERVAL)) {
 		sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
 
-		ieee80211_request_internal_scan(sdata,
-				ifibss->ssid, ifibss->ssid_len,
-				ifibss->fixed_channel ? ifibss->channel : NULL);
+		ieee80211_request_ibss_scan(sdata, ifibss->ssid,
+					    ifibss->ssid_len, chan);
 	} else {
 		int interval = IEEE80211_SCAN_INTERVAL;