regulator: userspace-consumer: quiet device deferral

Trying to use userspace-consumer when the required supplies have not yet
been probed will throw an error message on deferral:
reg-userspace-consumer output-led-power: Failed to get supplies: -517

So, lets simply use dev_err_probe() instead of dev_err() to not print
errors in case when driver probe is being deferred.

Signed-off-by: Robert Marko <robimarko@gmail.com>
Link: https://patch.msgid.link/20240623140947.1252376-1-robimarko@gmail.com


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