serial: vt8500: Fix range-checking on vt8500_uart_ports

Fix two instances where the index to vt8500_uart_ports is tested
against > VT8500_MAX_PORTS. Correct usage should be >= VT8500_MAX_PORTS.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c
index f1a398c..e50deb7 100644
--- a/drivers/tty/serial/vt8500_serial.c
+++ b/drivers/tty/serial/vt8500_serial.c
@@ -560,7 +560,7 @@
 
 	if (np)
 		port = of_alias_get_id(np, "serial");
-		if (port > VT8500_MAX_PORTS)
+		if (port >= VT8500_MAX_PORTS)
 			port = -1;
 	else
 		port = -1;
@@ -571,7 +571,7 @@
 					sizeof(vt8500_ports_in_use));
 	}
 
-	if (port > VT8500_MAX_PORTS)
+	if (port >= VT8500_MAX_PORTS)
 		return -ENODEV;
 
 	/* reserve the port id */