ixgbe: Fix bogus error message

If the VF sends a MACVLAN request with index of zero then it is not
actually trying to add a filter.  Check the index value and only
indicate that operation is not allowed when the VF is actually trying
to add a filter.
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c

@@ -640,14 +640,14 @@ static int ixgbe_rcv_msg_from_vf(struct ixgbe_adapter *adapter, u32 vf)
 		}
 		break;
 	case IXGBE_VF_SET_MACVLAN:
-		if (adapter->vfinfo[vf].pf_set_mac) {
+		index = (msgbuf[0] & IXGBE_VT_MSGINFO_MASK) >>
+			IXGBE_VT_MSGINFO_SHIFT;
+		if (adapter->vfinfo[vf].pf_set_mac && index > 0) {
 			e_warn(drv, "VF %d requested MACVLAN filter but is "
 				    "administratively denied\n", vf);
 			retval = -1;
 			break;
 		}
-		index = (msgbuf[0] & IXGBE_VT_MSGINFO_MASK) >>
-			IXGBE_VT_MSGINFO_SHIFT;
 		/*
 		 * If the VF is allowed to set MAC filters then turn off
 		 * anti-spoofing to avoid false positives.  An index