mwifiex: inform cfg80211 about disconnect if device is removed

If device is surprise removed, commands sent to FW including
deauthenticate command fail as bus writes fail.
We update our media_connected status to false and inform cfg80211
about disconnection only when command is successful. Since cfg80211
assumes device is still connected, it results into following
WARN_ON during unload:

WARNING: CPU: 0 PID: 18245 at net/wireless/core.c:937
         cfg80211_netdev_notifier_call+0x175/0x4d0 [cfg80211]()

Avoid this by emitting cfg80211_disconnected event even if the
deauthenticate command fails.
Signed-off-by: NAvinash Patil <patila@marvell.com>
Signed-off-by: NBing Zhao <bzhao@marvell.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/join.c

@@ -1422,13 +1422,19 @@ static int mwifiex_deauthenticate_infra(struct mwifiex_private *priv, u8 *mac)
  */
 int mwifiex_deauthenticate(struct mwifiex_private *priv, u8 *mac)
 {
+	int ret = 0;
+
 	if (!priv->media_connected)
 		return 0;
 
 	switch (priv->bss_mode) {
 	case NL80211_IFTYPE_STATION:
 	case NL80211_IFTYPE_P2P_CLIENT:
-		return mwifiex_deauthenticate_infra(priv, mac);
+		ret = mwifiex_deauthenticate_infra(priv, mac);
+		if (ret)
+			cfg80211_disconnected(priv->netdev, 0, NULL, 0,
+					      GFP_KERNEL);
+		break;
 	case NL80211_IFTYPE_ADHOC:
 		return mwifiex_send_cmd_sync(priv,
 					     HostCmd_CMD_802_11_AD_HOC_STOP,
@@ -1440,7 +1446,7 @@ int mwifiex_deauthenticate(struct mwifiex_private *priv, u8 *mac)
 		break;
 	}
 
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(mwifiex_deauthenticate);