net: cosmetic: Add a more explicit comment about 802.2

Make the comment more accurate about the header including SNAP

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/net/net.c b/net/net.c
index b8a267c..1293688 100644
--- a/net/net.c
+++ b/net/net.c
@@ -898,7 +898,8 @@
 	if (x < 1514) {
 		struct e802_hdr *et802 = (struct e802_hdr *)et;
 		/*
-		 *	Got a 802 packet.  Check the other protocol field.
+		 *	Got a 802.2 packet.  Check the other protocol field.
+		 *	XXX VLAN over 802.2+SNAP not implemented!
 		 */
 		x = ntohs(et802->et_prot);