[PATCH] libertas: access mesh_dev more carefully

The CF/SDIO firmware doesn't support Mesh, so priv->mesh_dev is
NULL there. Protect all accesses.

Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/libertas/join.c b/drivers/net/wireless/libertas/join.c
index f9799c3..da47c22 100644
--- a/drivers/net/wireless/libertas/join.c
+++ b/drivers/net/wireless/libertas/join.c
@@ -739,8 +739,10 @@
 	netif_carrier_on(priv->dev);
 	netif_wake_queue(priv->dev);
 
-	netif_carrier_on(priv->mesh_dev);
-	netif_wake_queue(priv->mesh_dev);
+	if (priv->mesh_dev) {
+		netif_carrier_on(priv->mesh_dev);
+		netif_wake_queue(priv->mesh_dev);
+	}
 
 	lbs_deb_join("ASSOC_RESP: Associated \n");
 
@@ -827,8 +829,10 @@
 	netif_carrier_on(priv->dev);
 	netif_wake_queue(priv->dev);
 
-	netif_carrier_on(priv->mesh_dev);
-	netif_wake_queue(priv->mesh_dev);
+	if (priv->mesh_dev) {
+		netif_carrier_on(priv->mesh_dev);
+		netif_wake_queue(priv->mesh_dev);
+	}
 
 	memset(&wrqu, 0, sizeof(wrqu));
 	memcpy(wrqu.ap_addr.sa_data, adapter->curbssparams.bssid, ETH_ALEN);