i40e: make error message more useful

BugLink: http://bugs.launchpad.net/bugs/1536474

If we get an invalid message from a VF, we should tell the user which VF
is being naughty, rather than making them guess.

Change-ID: I9252cef7baea3d8584043ed6ff12619a94e2f99c
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit e7ffb72d)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

@@ -1094,8 +1094,8 @@ static int i40e_vc_send_msg_to_vf(struct i40e_vf *vf, u32 v_opcode,
 	/* single place to detect unsuccessful return values */
 	if (v_retval) {
 		vf->num_invalid_msgs++;
-		dev_err(&pf->pdev->dev, "Failed opcode %d Error: %d\n",
-			v_opcode, v_retval);
+		dev_err(&pf->pdev->dev, "VF %d failed opcode %d, error: %d\n",
+			vf->vf_id, v_opcode, v_retval);
 		if (vf->num_invalid_msgs >
 		    I40E_DEFAULT_NUM_INVALID_MSGS_ALLOWED) {
 			dev_err(&pf->pdev->dev,