net: variables reach -1, but 0 tested

while (timeout--) { ... }

timeout becomes -1 if the loop isn't ended otherwise, not 0.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/sungem.c

@@ -148,7 +148,7 @@ static u16 __phy_read(struct gem *gp, int phy_addr, int reg)
 	cmd |= (MIF_FRAME_TAMSB);
 	writel(cmd, gp->regs + MIF_FRAME);
 
-	while (limit--) {
+	while (--limit) {
 		cmd = readl(gp->regs + MIF_FRAME);
 		if (cmd & MIF_FRAME_TALSB)
 			break;