sony-laptop - fix using of uninitialized variable

CC [M]  drivers/platform/x86/sony-laptop.o
drivers/platform/x86/sony-laptop.c: In function 'sony_nc_rfkill_setup':
drivers/platform/x86/sony-laptop.c:1162: warning: 'i' may be used uninitialized in this function

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/platform/x86/sony-laptop.c

@@ -1201,9 +1201,12 @@ static void sony_nc_rfkill_setup(struct acpi_device *device)
 	/* the buffer is filled with magic numbers describing the devices
 	 * available, 0xff terminates the enumeration
 	 */
-	while ((dev_code = *(device_enum->buffer.pointer + i)) != 0xff &&
-			i < device_enum->buffer.length) {
-		i++;
+	for (i = 0; i < device_enum->buffer.length; i++) {
+
+		dev_code = *(device_enum->buffer.pointer + i);
+		if (dev_code == 0xff)
+			break;
+
 		dprintk("Radio devices, looking at 0x%.2x\n", dev_code);
 
 		if (dev_code == 0 && !sony_rfkill_devices[SONY_WIFI])