openvswitch: remove some useless comments

These comments are useless in upstream kernel.

Cc: David S. Miller <davem@davemloft.net>
Cc: Jesse Gross <jesse@nicira.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index 70af0be..6255e48 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -326,8 +326,7 @@
  * @skb: skb that was received
  *
  * Must be called with rcu_read_lock.  The packet cannot be shared and
- * skb->data should point to the Ethernet header.  The caller must have already
- * called compute_ip_summed() to initialize the checksumming fields.
+ * skb->data should point to the Ethernet header.
  */
 void ovs_vport_receive(struct vport *vport, struct sk_buff *skb)
 {