regulator: remove redundant ret variable

Return value from regmap_update_bits() directly instead
of taking this in another redundant variable.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: CGEL ZTE <cgel.zte@gmail.com>
Link: https://lore.kernel.org/r/20220104104139.601031-1-chi.minghao@zte.com.cn


Signed-off-by: Mark Brown <broonie@kernel.org>