[TR]: Use tr_hdr() were appropriate

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/802/tr.c b/net/802/tr.c
index 96bd144..a6a6d46 100644
--- a/net/802/tr.c
+++ b/net/802/tr.c
@@ -189,11 +189,12 @@
 __be16 tr_type_trans(struct sk_buff *skb, struct net_device *dev)
 {
 
-	struct trh_hdr *trh=(struct trh_hdr *)skb->data;
+	struct trh_hdr *trh;
 	struct trllc *trllc;
 	unsigned riflen=0;
 
 	skb->mac.raw = skb->data;
+	trh = tr_hdr(skb);
 
 	if(trh->saddr[0] & TR_RII)
 		riflen = (ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8;