regulator: gpio: Use dev_err_probe

During probe the gpio driver may not yet be available. Use
dev_err_probe to provide just the pertinent log.

Since dev_err_probe takes care of reporting the error value,
drop the redundant ret variable while at it.

Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://patch.msgid.link/20250512185727.2907411-1-nm@ti.com


Signed-off-by: Mark Brown <broonie@kernel.org>