mac80211: make multicast variable a bool in ieee80211_accept_frame()

The multicast variable in the ieee80211_accept_frame() function is
treated as a boolean, but defined as int.  Fix that.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 0094f3c..fe6a760 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -3574,7 +3574,7 @@
 	struct ieee80211_hdr *hdr = (void *)skb->data;
 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
-	int multicast = is_multicast_ether_addr(hdr->addr1);
+	bool multicast = is_multicast_ether_addr(hdr->addr1);
 
 	switch (sdata->vif.type) {
 	case NL80211_IFTYPE_STATION: