cmd: gpio: use correct printf code

gpio is defined as unsigned int. So we should use %u when calling printf().

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/gpio.c b/cmd/gpio.c
index ecdc453..c60946b 100644
--- a/cmd/gpio.c
+++ b/cmd/gpio.c
@@ -213,7 +213,7 @@
 		}
 		gpio_direction_output(gpio, value);
 	}
-	printf("gpio: pin %s (gpio %i) value is ", str_gpio, gpio);
+	printf("gpio: pin %s (gpio %u) value is ", str_gpio, gpio);
 	if (IS_ERR_VALUE(value))
 		printf("unknown (ret=%d)\n", value);
 	else