net: dsa: hellcreek: fix missing error handling in LED registration

net: dsa: hellcreek: fix missing error handling in LED registration

The LED setup routine registered both led_sync_good
and led_is_gm devices without checking the return
values of led_classdev_register(). If either registration
failed, the function continued silently, leaving the
driver in a partially-initialized state and leaking
a registered LED classdev.

Add proper error handling

Fixes: 7d9ee2e8ff15 ("net: dsa: hellcreek: Add PTP status LEDs")
Signed-off-by: Pavel Zhigulin <Pavel.Zhigulin@kaspersky.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Kurt Kanzenbach <kurt@linutronix.de>
Link: https://patch.msgid.link/20251113135745.92375-1-Pavel.Zhigulin@kaspersky.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>