mac80211: tx: avoid variable shadowing

We have a bool and an __le16 called qos, rename the inner __le16
to 'qoshdr' to make it more obvious and to avoid sparse warnings.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/tx.c

@@ -4579,7 +4579,7 @@ struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
 					      IEEE80211_STYPE_NULLFUNC |
 					      IEEE80211_FCTL_TODS);
 	if (qos) {
-		__le16 qos = cpu_to_le16(7);
+		__le16 qoshdr = cpu_to_le16(7);
 
 		BUILD_BUG_ON((IEEE80211_STYPE_QOS_NULLFUNC |
 			      IEEE80211_STYPE_NULLFUNC) !=
@@ -4588,7 +4588,7 @@ struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
 			cpu_to_le16(IEEE80211_STYPE_QOS_NULLFUNC);
 		skb->priority = 7;
 		skb_set_queue_mapping(skb, IEEE80211_AC_VO);
-		skb_put_data(skb, &qos, sizeof(qos));
+		skb_put_data(skb, &qoshdr, sizeof(qoshdr));
 	}
 
 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);