r8169: speed up rtl_loop_wait

When testing I figured out that most operations signal finish even
before we trigger the first delay. Seems like PCI(e) access and
memory barriers typically add enough latency. Therefore move the
first delay after the first check.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169.c

@@ -775,9 +775,9 @@ static bool rtl_loop_wait(struct rtl8169_private *tp, const struct rtl_cond *c,
 	int i;
 
 	for (i = 0; i < n; i++) {
-		delay(d);
 		if (c->check(tp) == high)
 			return true;
+		delay(d);
 	}
 	netif_err(tp, drv, tp->dev, "%s == %d (loop: %d, delay: %d).\n",
 		  c->msg, !high, n, d);