gpiolib: do not print err message for EPROBE_DEFER

The gpiochip may have dependencies from pinmux and so got deferred. Now it
will print error message every time -EPROBE_DEFER is returned which is
unnecessary:

"gpiochip_add_data_with_key: GPIOs 0..31 (gpio-0-31) failed to register, -517"

Hence, do suppress error message for -EPROBE_DEFER case.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/gpiolib.c

@@ -759,9 +759,11 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
 	ida_free(&gpio_ida, gdev->id);
 err_free_gdev:
 	/* failures here can mean systems won't boot... */
-	pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
-	       gdev->base, gdev->base + gdev->ngpio - 1,
-	       gc->label ? : "generic", ret);
+	if (ret != -EPROBE_DEFER) {
+		pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
+		       gdev->base, gdev->base + gdev->ngpio - 1,
+		       gc->label ? : "generic", ret);
+	}
 	kfree(gdev);
 	return ret;
 }