opp: Fix early exit from dev_pm_opp_register_set_opp_helper()

We returned earlier by mistake even when there were no failures. Fix it.

Fixes: dd461cd9 ("opp: Allow dev_pm_opp_get_opp_table() to return -EPROBE_DEFER")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.com>