ethernet: fix dmac stride error

Type: fix

Signed-off-by: Zhiyong Yang <zhiyong.yang@intel.com>
Change-Id: I617fb365def22a28d48f75013dea38f8e1703a44
diff --git a/src/vnet/ethernet/node.c b/src/vnet/ethernet/node.c
index 5136da4..3c4330e 100755
--- a/src/vnet/ethernet/node.c
+++ b/src/vnet/ethernet/node.c
@@ -902,7 +902,7 @@
       n_left -= 1;
       etype += 1;
       tag += 1;
-      dmac += 4;
+      dmac += 1;
     }
 
   if (dmac_check)