batman-adv: convert bat_priv->tt_crc from atomic_t to uint16_t

In the code we neever need to atomically check and set the bat_priv->tt_crc
field value. It is simply set and read once in different pieces of the code.
Therefore this field can be safely be converted from atomic_t to uint16_t.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index dc53798..ec35119 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -575,8 +575,7 @@
 			htonl((uint32_t)atomic_read(&hard_iface->seqno));
 
 	batman_ogm_packet->ttvn = atomic_read(&bat_priv->ttvn);
-	batman_ogm_packet->tt_crc = htons((uint16_t)
-						atomic_read(&bat_priv->tt_crc));
+	batman_ogm_packet->tt_crc = htons(bat_priv->tt_crc);
 	if (tt_num_changes >= 0)
 		batman_ogm_packet->tt_num_changes = tt_num_changes;