vxlan: fix potential NULL dereference in arp_reduce()

This patch fixes a NULL pointer dereference in the event of an
skb allocation failure in arp_reduce().

Signed-Off-By: David L Stevens <dlstevens@us.ibm.com>
Acked-by: Cong Wang <cwang@twopensource.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index b0f705c..a7eb3f2 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1318,6 +1318,9 @@
 
 		neigh_release(n);
 
+		if (reply == NULL)
+			goto out;
+
 		skb_reset_mac_header(reply);
 		__skb_pull(reply, skb_network_offset(reply));
 		reply->ip_summed = CHECKSUM_UNNECESSARY;