i2c: Test off by one in {piix4,vt596}_transaction()

With `while (timeout++ < MAX_TIMEOUT)' timeout reaches MAX_TIMEOUT + 1
after the loop. This is probably unlikely to produce a problem.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

drivers/i2c/busses/i2c-piix4.c

@@ -324,12 +324,12 @@ static int piix4_transaction(void)
 	else
 		msleep(1);
 
-	while ((timeout++ < MAX_TIMEOUT) &&
+	while ((++timeout < MAX_TIMEOUT) &&
 	       ((temp = inb_p(SMBHSTSTS)) & 0x01))
 		msleep(1);
 
 	/* If the SMBus is still busy, we give up */
-	if (timeout >= MAX_TIMEOUT) {
+	if (timeout == MAX_TIMEOUT) {
 		dev_err(&piix4_adapter.dev, "SMBus Timeout!\n");
 		result = -ETIMEDOUT;
 	}

drivers/i2c/busses/i2c-viapro.c

@@ -165,10 +165,10 @@ static int vt596_transaction(u8 size)
 	do {
 		msleep(1);
 		temp = inb_p(SMBHSTSTS);
-	} while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
+	} while ((temp & 0x01) && (++timeout < MAX_TIMEOUT));
 
 	/* If the SMBus is still busy, we give up */
-	if (timeout >= MAX_TIMEOUT) {
+	if (timeout == MAX_TIMEOUT) {
 		result = -ETIMEDOUT;
 		dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
 	}