tty: serial: max3100: Fix error case

We don't want to free a random address if the entry is wrong, cover
this and WARN if it ever happens.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/max3100.c

@@ -827,13 +827,15 @@ static int __devexit max3100_remove(struct spi_device *spi)
 
 	/* find out the index for the chip we are removing */
 	for (i = 0; i < MAX_MAX3100; i++)
-		if (max3100s[i] == s)
-			break;
-
+		if (max3100s[i] == s) {
 			dev_dbg(&spi->dev, "%s: removing port %d\n", __func__, i);
 			uart_remove_one_port(&max3100_uart_driver, &max3100s[i]->port);
 			kfree(max3100s[i]);
 			max3100s[i] = NULL;
+			break;
+		}
+
+	WARN_ON(i == MAX_MAX3100);
 	
 	/* check if this is the last chip we have */
 	for (i = 0; i < MAX_MAX3100; i++)