devfreq: rk3399_dmc: Remove dangling rcu_read_unlock()

This call never had the rcu_read_lock() counterpart. Remove the unlock
part as well.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/devfreq/rk3399_dmc.c

@@ -414,7 +414,6 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
 	 */
 	if (dev_pm_opp_of_add_table(dev)) {
 		dev_err(dev, "Invalid operating-points in device tree.\n");
-		rcu_read_unlock();
 		return -EINVAL;
 	}