net/cadence/macb: fix bug/typo in extracting gem_irq_read_clear bit

Signed-off-by: NJongsung Kim <neidhard.kim@lge.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/cadence/macb.c

@@ -1292,7 +1292,7 @@ static void macb_configure_dma(struct macb *bp)
 static void macb_configure_caps(struct macb *bp)
 {
 	if (macb_is_gem(bp)) {
-		if (GEM_BF(IRQCOR, gem_readl(bp, DCFG1)) == 0)
+		if (GEM_BFEXT(IRQCOR, gem_readl(bp, DCFG1)) == 0)
 			bp->caps |= MACB_CAPS_ISR_CLEAR_ON_WRITE;
 	}
 }