platform/x86/amd/pmf: Return directly after a failed apmf_if_call() in apmf_sbios_hea...

platform/x86/amd/pmf: Return directly after a failed apmf_if_call() in apmf_sbios_heartbeat_notify()

The kfree() function was called in one case by
the apmf_sbios_heartbeat_notify() function during error handling
even if the passed variable contained a null pointer.
This issue was detected by using the Coccinelle software.

* Thus return directly after a call of the function “apmf_if_call” failed
  at the beginning.

* Delete the label “out” which became unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Link: https://lore.kernel.org/r/362ee824-fc53-4e19-9529-8b621657635b@web.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>