virtio: Fix typo in virtio_net_hdr comments

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

include/linux/virtio_net.h

@@ -38,7 +38,7 @@ struct virtio_net_hdr
 #define VIRTIO_NET_HDR_GSO_ECN		0x80	// TCP has ECN set
 	__u8 gso_type;
 	__u16 hdr_len;		/* Ethernet + IP + tcp/udp hdrs */
-	__u16 gso_size;		/* Bytes to append to gso_hdr_len per frame */
+	__u16 gso_size;		/* Bytes to append to hdr_len per frame */
 	__u16 csum_start;	/* Position to start checksumming from */
 	__u16 csum_offset;	/* Offset after that to place checksum */
 };