ptp: vmclock: Remove goto-based cleanup logic

vmclock_probe() uses an "out:" label to return from the function on
error. This indicates that some cleanup operation is necessary.
However the label does not do anything as all resources are managed
through devres, making the code slightly harder to read.

Remove the label and just return directly.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>