pinctrl: renesas: rzg2l: remove unnecessary check from rzg2l_dt_node_to_map()

This patch removes the unnecessary check from rzg2l_dt_node_to_map()
as the ret value is already negative.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20221108191309.3908415-1-biju.das.jz@bp.renesas.com


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