regulator: core: fix error path for regulator_set_voltage_unlocked

regulator: core: fix error path for regulator_set_voltage_unlocked

During several error paths in the function
regulator_set_voltage_unlocked() the value of 'ret' can take on negative
error values. However, in calls that go through the 'goto out' statement,
this return value is lost and return 0 is used instead, indicating a
'pass'.

There are several cases where this function should legitimately return a
fail instead of a pass: one such case includes constraints check during
voltage selection in the call to regulator_check_voltage(), which can
have -EINVAL for the case when an unsupported voltage is incorrectly
requested. In that case, -22 is expected as the return value, not 0.

Fixes: 9243a195be7a ("regulator: core: Change voltage setting path")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>