power-supply: Avoid unnecessary 'goto' statements

Using 'goto' statements for freeing resources on failures is a good choice as it
makes code very clean, and reduces the chances of human errors.

Though in most cases compiler may take care of this. But adding unnecessary
'goto' statements wouldn't make anything better. Code becomes less readable
actually.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>