ASoC: sgtl5000: use after free in ldo_regulator_register()

The "ldo" variable was dereferenced after free on the error path.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>