thermal: fix multiple disbalanced device node counters

Here on function return all temporarily used device nodes shall
decrement their usage counter. The problems are found with device
nodes allocated by for_each_child_of_node(), of_parse_phandle()
and of_find_node_by_name(), fix all problems at once.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: devicetree@vger.kernel.org
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>