dev_pm_genpd_set_performance_state() may fail, so had better to check it's
return value before decreasing priv->enable_counter.

Fixes: bf3a28cf ("regulator: fixed: support using power domain for enable/disable")
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/20210520111811.1806293-1-axel.lin@ingics.comSigned-off-by: NMark Brown <broonie@kernel.org>