[XFRM]: Avoid bogus BUG() when throwing new policy away.

From: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

When we destory a new policy entry, we need to tell
xfrm_policy_destroy() explicitly that the entry is not
alive yet.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 7833807..f971ca5 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1105,6 +1105,7 @@
 	return xp;
  error:
 	*errp = err;
+	xp->dead = 1;
 	xfrm_policy_destroy(xp);
 	return NULL;
 }