regulator: qpnp: fix memory leak when probe failed

This patch fixes the following sparse warnings:
qpnp-regulator.c:2187 qpnp_regulator_probe() warn:
possible memory leak of 'vreg'

Bug: 77543262
Test: boot
Change-Id: I115e2c992f37e91fe9b31e7e475619bb679c1ee8
Signed-off-by: David Lin <dtwlin@google.com>

drivers/regulator/qpnp-regulator.c

@@ -2184,6 +2184,7 @@ static int qpnp_regulator_probe(struct platform_device *pdev)
 	vreg->regmap = dev_get_regmap(pdev->dev.parent, NULL);
 	if (!vreg->regmap) {
 		dev_err(&pdev->dev, "Couldn't get parent's regmap\n");
+		kfree(vreg);
 		return -EINVAL;
 	}