ravb: make ravb_ptp_interrupt() *void*

When we have the ISS.CGIS bit set, we already know that gPTP interrupt has
happened, so an extra GIS register check at the end of ravb_ptp_interrupt()
seems superfluous.  We can model the gPTP interrupt  handler like all other
dedicated interrupt handlers in the driver and make it *void*.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 4b71951..0f1b314 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -807,8 +807,10 @@
 	}
 
 	/* gPTP interrupt status summary */
-	if ((iss & ISS_CGIS) && ravb_ptp_interrupt(ndev) == IRQ_HANDLED)
+	if (iss & ISS_CGIS) {
+		ravb_ptp_interrupt(ndev);
 		result = IRQ_HANDLED;
+	}
 
 	mmiowb();
 	spin_unlock(&priv->lock);
@@ -838,8 +840,10 @@
 	}
 
 	/* gPTP interrupt status summary */
-	if ((iss & ISS_CGIS) && ravb_ptp_interrupt(ndev) == IRQ_HANDLED)
+	if (iss & ISS_CGIS) {
+		ravb_ptp_interrupt(ndev);
 		result = IRQ_HANDLED;
+	}
 
 	mmiowb();
 	spin_unlock(&priv->lock);