regulator: make the dummy regulator's print_constraint more helpful

This prevents the output of just

	dummy:

in the boot log. Now it says:

	regulator-dummy: no parameters

which at least doesn't make it look like an accidental printk and also doesn't
only use "dummy" which could mean anything.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/regulator/core.c

@@ -778,6 +778,9 @@ static void print_constraints(struct regulator_dev *rdev)
 	if (constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
 		count += sprintf(buf + count, "standby");
 
+	if (!count)
+		sprintf(buf, "no parameters");
+
 	rdev_info(rdev, "%s\n", buf);
 
 	if ((constraints->min_uV != constraints->max_uV) &&

drivers/regulator/dummy.c

@@ -30,7 +30,7 @@ static struct regulator_init_data dummy_initdata;
 static struct regulator_ops dummy_ops;
 
 static struct regulator_desc dummy_desc = {
-	.name = "dummy",
+	.name = "regulator-dummy",
 	.id = -1,
 	.type = REGULATOR_VOLTAGE,
 	.owner = THIS_MODULE,