Revert "thermal/core: Deprecate changing cooling device state from userspace"

This reverts commit a67a46a.

It has been reported the warning is annoying as the cooling device
state is still needed on some production system.

Meanwhile we provide a way to consolidate the thermal framework to
prevent multiple actors acting on the cooling devices with conflicting
decisions, let's revert this warning.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: dlezcano

drivers/thermal/thermal_sysfs.c

@@ -610,9 +610,6 @@ cur_state_store(struct device *dev, struct device_attribute *attr,
 	unsigned long state;
 	int result;
 
-	dev_warn_once(&cdev->device,
-		      "Setting cooling device state is deprecated\n");
-	
 	if (sscanf(buf, "%ld\n", &state) != 1)
 		return -EINVAL;