net: fsl: Don't use NO_IRQ to check return value of irq_of_parse_and_map()

This driver can be built on arm64 but relies on NO_IRQ to check the return
value of irq_of_parse_and_map() which fails to build on arm64 because the
architecture does not provide a NO_IRQ. Fix this to correctly check the
return value of irq_of_parse_and_map().

Even on ARM systems where the driver was previously used the check was
broken since on ARM NO_IRQ is -1 but irq_of_parse_and_map() returns 0 on
error.
Signed-off-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/gianfar.c

@@ -647,9 +647,9 @@ static int gfar_parse_group(struct device_node *np,
 	if (model && strcasecmp(model, "FEC")) {
 		gfar_irq(grp, RX)->irq = irq_of_parse_and_map(np, 1);
 		gfar_irq(grp, ER)->irq = irq_of_parse_and_map(np, 2);
-		if (gfar_irq(grp, TX)->irq == NO_IRQ ||
-		    gfar_irq(grp, RX)->irq == NO_IRQ ||
-		    gfar_irq(grp, ER)->irq == NO_IRQ)
+		if (!gfar_irq(grp, TX)->irq ||
+		    !gfar_irq(grp, RX)->irq ||
+		    !gfar_irq(grp, ER)->irq)
 			return -EINVAL;
 	}