regulator: of: Add of_node_put() before return in function

The local variable search in regulator_of_get_init_node takes the value
returned by either of_get_child_by_name or of_node_get, both of which
get a node. If this node is not put before returning, it could cause a
memory leak. Hence put search before a mid-loop return statement.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Link: https://lore.kernel.org/r/20190724083231.10276-1-nishkadg.linux@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>