rtl818x: fix sparse warnings

This silences a few sparse warnings. There are two more where
I can't follow the code.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rtl8180_dev.c

@@ -135,13 +135,15 @@ static void rtl8180_handle_tx(struct ieee80211_hw *dev, unsigned int prio)
 	while (skb_queue_len(&ring->queue)) {
 		struct rtl8180_tx_desc *entry = &ring->desc[ring->idx];
 		struct sk_buff *skb;
-		struct ieee80211_tx_status status = { {0} };
+		struct ieee80211_tx_status status;
 		struct ieee80211_tx_control *control;
 		u32 flags = le32_to_cpu(entry->flags);
 
 		if (flags & RTL8180_TX_DESC_FLAG_OWN)
 			return;
 
+		memset(&status, 0, sizeof(status));
+
 		ring->idx = (ring->idx + 1) % ring->entries;
 		skb = __skb_dequeue(&ring->queue);
 		pci_unmap_single(priv->pdev, le32_to_cpu(entry->tx_buf),

drivers/net/wireless/rtl8187_dev.c

@@ -113,10 +113,12 @@ void rtl8187_write_phy(struct ieee80211_hw *dev, u8 addr, u32 data)
 
 static void rtl8187_tx_cb(struct urb *urb)
 {
-	struct ieee80211_tx_status status = { {0} };
+	struct ieee80211_tx_status status;
 	struct sk_buff *skb = (struct sk_buff *)urb->context;
 	struct rtl8187_tx_info *info = (struct rtl8187_tx_info *)skb->cb;
 
+	memset(&status, 0, sizeof(status));
+
 	usb_free_urb(info->urb);
 	if (info->control)
 		memcpy(&status.control, info->control, sizeof(status.control));