Fix implicit nocast warnings in ieee80211 code:

net/ieee80211/ieee80211_tx.c:215:9: warning: implicit cast to nocast type
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: James Ketrenos <jketreno@linux.intel.com>

net/ieee80211/ieee80211_tx.c

@@ -187,7 +187,7 @@ void ieee80211_txb_free(struct ieee80211_txb *txb)
 }
 
 static struct ieee80211_txb *ieee80211_alloc_txb(int nr_frags, int txb_size,
-						 int gfp_mask)
+						 unsigned int gfp_mask)
 {
 	struct ieee80211_txb *txb;
 	int i;