wl12xx: check bss_conf->assoc on CHANGED_BSSID

with the new auth/assoc redesign, we get CHANGED_BSSID
indication before CHANGED_ASSOC indication, while our
CHANGED_BSSID handling block assumes we are already
associated.

Fix it by checking we are either in ibss mode, or
already associated.

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/wl12xx/main.c b/drivers/net/wireless/wl12xx/main.c
index ce0a233..bba2a52 100644
--- a/drivers/net/wireless/wl12xx/main.c
+++ b/drivers/net/wireless/wl12xx/main.c
@@ -3665,7 +3665,8 @@
 		wlvif->rssi_thold = bss_conf->cqm_rssi_thold;
 	}
 
-	if (changed & BSS_CHANGED_BSSID)
+	if (changed & BSS_CHANGED_BSSID &&
+	    (is_ibss || bss_conf->assoc))
 		if (!is_zero_ether_addr(bss_conf->bssid)) {
 			ret = wl12xx_cmd_build_null_data(wl, wlvif);
 			if (ret < 0)