pinctrl: renesas: rzg2l: Fix missing return in rzg2l_pinctrl_register()

Fix the missing return statement in the error path of
rzg2l_pinctrl_register().

Fixes: f73f63b2 ("pinctrl: renesas: rzg2l: Use dev_err_probe()")
Reported-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Closes: https://lore.kernel.org/all/OS0PR01MB638837327E5487B71D88A70392712@OS0PR01MB6388.jpnprd01.prod.outlook.com/


Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/20241003082550.33341-1-biju.das.jz@bp.renesas.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>