net: fec: return IRQ_HANDLED if fec_ptp_check_pps_event handled it

fec_ptp_check_pps_event will return 1 if FEC_T_TF_MASK caused
an interrupt. Don't return IRQ_NONE in this case.

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fec_main.c

@@ -1604,8 +1604,8 @@ fec_enet_interrupt(int irq, void *dev_id)
 	}
 
 	if (fep->ptp_clock)
-		fec_ptp_check_pps_event(fep);
-
+		if (fec_ptp_check_pps_event(fep))
+			ret = IRQ_HANDLED;
 	return ret;
 }