watchdog: rzg2l_wdt: Remove comparison with zero

devm_add_action_or_reset() could return -ENOMEM or zero. Thus, remove
comparison with zero of the returning value to make code simpler.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20240531065723.1085423-7-claudiu.beznea.uj@bp.renesas.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>