When it uses regulators the mms114 driver checks to see if it managed to
acquire regulators and ignores errors. This is not the intended usage and
not great style in general.

Since the driver already refuses to probe if it fails to allocate the
regulators simply make the enable and disable calls unconditional and
add appropriate error handling, including adding cleanup of the
regulators if setup_reg() fails.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>