net: use __packed annotation

cleanup patch.

Use new __packed annotation in net/ and include/
(except netfilter)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index c7000a6..a2ed0f7b 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -600,7 +600,7 @@
 	u8 ssap;		/* 0 */
 	u8 control;
 	u8 xid_info[3];
-} __attribute__ ((packed));
+} __packed;
 
 static void ieee80211_send_layer2_update(struct sta_info *sta)
 {