broadcom: b44: Use b44_writephy() return value

Return result of b44_writephy() instead of zero to
deal with possible error.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/b44.c

@@ -1793,11 +1793,9 @@ static int b44_nway_reset(struct net_device *dev)
 	b44_readphy(bp, MII_BMCR, &bmcr);
 	b44_readphy(bp, MII_BMCR, &bmcr);
 	r = -EINVAL;
-	if (bmcr & BMCR_ANENABLE) {
-		b44_writephy(bp, MII_BMCR,
-			     bmcr | BMCR_ANRESTART);
-		r = 0;
-	}
+	if (bmcr & BMCR_ANENABLE)
+		r = b44_writephy(bp, MII_BMCR,
+				 bmcr | BMCR_ANRESTART);
 	spin_unlock_irq(&bp->lock);
 
 	return r;