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/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 42d0d02..112bb61 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1329,9 +1329,9 @@
 
 /* scan/BSS handling */
 void ieee80211_scan_work(struct work_struct *work);
-int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
-				    const u8 *ssid, u8 ssid_len,
-				    struct ieee80211_channel *chan);
+int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
+				const u8 *ssid, u8 ssid_len,
+				struct ieee80211_channel *chan);
 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
 			   struct cfg80211_scan_request *req);
 void ieee80211_scan_cancel(struct ieee80211_local *local);