ath6kl: fix uninitialized warning in ath6kl_process_uapsdq()

Before I commited patch c1762a3f ("ath6kl: Add support for uAPSD") I
did a minor change how up variable is initialised in
ath6kl_process_uapsdq(). But I was sloppy and caused this compiler
warning:

txrx.c:88:5: warning: 'up' may be used uninitialized in this function

Revert my change to fix the warning.
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath6kl/txrx.c

@@ -85,7 +85,7 @@ static bool ath6kl_process_uapsdq(struct ath6kl_sta *conn,
 	struct ath6kl *ar = vif->ar;
 	bool is_apsdq_empty = false;
 	struct ethhdr *datap = (struct ethhdr *) skb->data;
-	u8 up, traffic_class, *ip_hdr;
+	u8 up = 0, traffic_class, *ip_hdr;
 	u16 ether_type;
 	struct ath6kl_llc_snap_hdr *llc_hdr;
 
@@ -122,8 +122,6 @@ static bool ath6kl_process_uapsdq(struct ath6kl_sta *conn,
 		if (ether_type == IP_ETHERTYPE)
 			up = ath6kl_wmi_determine_user_priority(
 							ip_hdr, 0);
-	} else {
-		up = 0;
 	}
 
 	traffic_class = ath6kl_wmi_get_traffic_class(up);