leds: netxbig: Fix an OF node reference leak in netxbig_leds_get_of_pdata()

leds: netxbig: Fix an OF node reference leak in netxbig_leds_get_of_pdata()

netxbig_leds_get_of_pdata() does not release the OF node obtained by
of_parse_phandle() when of_find_device_by_node() fails. Add an
of_node_put() call to fix the leak.

This bug was found by an experimental static analysis tool that I am
developing.

Fixes: 9af512e81964 ("leds: netxbig: Convert to use GPIO descriptors")
Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Link: https://lore.kernel.org/r/20241216074923.628509-1-joe@pf.is.s.u-tokyo.ac.jp
Signed-off-by: Lee Jones <lee@kernel.org>