staging: pi433: replace unsigned with unsigned int

Fixes checkpatch warning:

  WARNING: Prefer 'unsigned int' to bare use of 'unsigned'

Signed-off-by: Valentin Vidic <Valentin.Vidic@CARNet.hr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/pi433/pi433_if.c

@@ -78,7 +78,7 @@ struct pi433_device {
 	struct device		*dev;
 	struct cdev		*cdev;
 	struct spi_device	*spi;
-	unsigned		users;
+	unsigned int		users;
 
 	/* irq related values */
 	struct gpio_desc	*gpiod[NUM_DIO];