wcn36xx: initialize dxe lock

The dxe lock is missing its initialization, so add it.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/drivers/net/wireless/ath/wcn36xx/main.c b/drivers/net/wireless/ath/wcn36xx/main.c
index 7dd8873..972bb3e 100644
--- a/drivers/net/wireless/ath/wcn36xx/main.c
+++ b/drivers/net/wireless/ath/wcn36xx/main.c
@@ -298,6 +298,8 @@
 	wcn36xx_debugfs_init(wcn);
 
 	INIT_LIST_HEAD(&wcn->vif_list);
+	spin_lock_init(&wcn->dxe_lock);
+
 	return 0;
 
 out_smd_stop: