regulator: fix crash caused by null driver data

dev_set_drvdata() needs to be called before device_register()
exposes device to userspace. Otherwise kernel crashes after it
gets null pointer from dev_get_drvdata() when userspace tries
to access sysfs entries.

[Removed backtrace for length -- broonie]
Signed-off-by: NYu Zhao <yuzhao@google.com>
Signed-off-by: NMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

drivers/regulator/core.c

@@ -4395,13 +4395,13 @@ regulator_register(const struct regulator_desc *regulator_desc,
 	    !rdev->desc->fixed_uV)
 		rdev->is_switch = true;
 
+	dev_set_drvdata(&rdev->dev, rdev);
 	ret = device_register(&rdev->dev);
 	if (ret != 0) {
 		put_device(&rdev->dev);
 		goto unset_supplies;
 	}
 
-	dev_set_drvdata(&rdev->dev, rdev);
 	rdev_init_debugfs(rdev);
 
 	/* try to resolve regulators supply since a new one was registered */