mac80211: use fixed broadcast address

The netdev broadcast address cannot change from
all-ones so there's no need to use it; we can
instead hard-code it. Since we already have an
instance in tkip.c, which will be shared if it
is marked static const, doing this reduces text
size at no data/bss cost.

The real motivation for this is, of course, the
desire to get rid of almost all uses of netdevs
in mac80211 so that auditing their use becomes
easier.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index bbd56b0..3a0683b 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -394,8 +394,9 @@
  *
  * Return the length of the 802.11 (does not include a mesh control header)
  */
-int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc, char
-		*meshda, char *meshsa) {
+int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
+				  const u8 *meshda, const u8 *meshsa)
+{
 	if (is_multicast_ether_addr(meshda)) {
 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
 		/* DA TA SA */