Fix DPDK check in udp.h

Change-Id: I4734b248f512e223703d234d28542257af1a8074
Signed-off-by: Florin Coras <fcoras@cisco.com>
diff --git a/vnet/vnet/ip/udp.h b/vnet/vnet/ip/udp.h
index e9ee1e3..3aedf67 100644
--- a/vnet/vnet/ip/udp.h
+++ b/vnet/vnet/ip/udp.h
@@ -124,7 +124,7 @@
   ip0 = vlib_buffer_get_current(b0);
 
   /* Apply the encap string. */
-#if DPDK
+#if DPDK > 0
   rte_memcpy(ip0, ec0, ec_len);
 #else
   memcpy(ip0, ec0, ec_len);
@@ -167,7 +167,7 @@
   ip1 = vlib_buffer_get_current (b1);
 
   /* Apply the encap string */
-#ifdef DPDK
+#if DPDK > 0
   rte_memcpy (ip0, ec0, ec_len);
   rte_memcpy (ip1, ec1, ec_len);
 #else