mwifiex: abort scan upon interface down

When the interface is down, we will abort scan by calling
cfg80211_scan_done() with abort option. This fixes WARN_ON
triggered by cfg80211 in wdev_cleanup_work().

Driver's internal variables/flags are cleared once we get
response for current scan command. Meanwhile we will block
new scan request from cfg80211.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/mwifiex/init.c b/drivers/net/wireless/mwifiex/init.c
index b5d37a8..37f2d95 100644
--- a/drivers/net/wireless/mwifiex/init.c
+++ b/drivers/net/wireless/mwifiex/init.c
@@ -84,10 +84,16 @@
 		spin_unlock_irqrestore(&adapter->mwifiex_cmd_lock, flags);
 
 		if (priv->user_scan_cfg) {
-			dev_dbg(priv->adapter->dev,
-				"info: %s: scan aborted\n", __func__);
-			cfg80211_scan_done(priv->scan_request, 1);
-			priv->scan_request = NULL;
+			if (priv->scan_request) {
+				dev_dbg(priv->adapter->dev,
+					"info: aborting scan\n");
+				cfg80211_scan_done(priv->scan_request, 1);
+				priv->scan_request = NULL;
+			} else {
+				dev_dbg(priv->adapter->dev,
+					"info: scan already aborted\n");
+			}
+
 			kfree(priv->user_scan_cfg);
 			priv->user_scan_cfg = NULL;
 		}