regulator: of: Fix refcount leak bug in of_get_regulation_constraints()

regulator: of: Fix refcount leak bug in of_get_regulation_constraints()

[ Upstream commit 66efb665cd5ad69b27dca8571bf89fc6b9c628a4 ]

We should call the of_node_put() for the reference returned by
of_get_child_by_name() which has increased the refcount.

Fixes: 40e20d68bb3f ("regulator: of: Add support for parsing regulator_state for suspend state")
Signed-off-by: Liang He <windhl@126.com>
Link: https://lore.kernel.org/r/20220715111027.391032-1-windhl@126.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>