[IPSEC]: Kill redundant dst_release check in xfrm_dst_destroy

Here's a trivial patch to get rid of a redundant check that I added
in patch 3/4.  dst_release already checks for dst == NULL.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/xfrm/xfrm_policy.c

@@ -1028,8 +1028,7 @@ static void xfrm_dst_destroy(struct dst_entry *dst)
 {
 	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
 
-	if (xdst->route)
-		dst_release(xdst->route);
+	dst_release(xdst->route);
 
 	if (!dst->xfrm)
 		return;