regulator: fix indentation issue

There is a return statement that is indented with an extra
space, fix this by removing it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200920142454.33352-1-colin.king@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>