Revert "ALSA: pcmtest: fix reference leak on failed device registration"

Revert "ALSA: pcmtest: fix reference leak on failed device registration"

We'd like to address the problem rather in the error code path of
platform_device_register() itself instead of leaving it all callers,
since less than 1% of all callers of over 100
platform_device_register() do call platform_device_put() properly as
of now.

For making the work easier, revert the previous change commit
4ff036f95238 ("ALSA: pcmtest: fix reference leak on failed device
registration") again.

Link: https://lore.kernel.org/20260415193138.3861297-1-lgs201920130244@gmail.com
Link: https://patch.msgid.link/20260423075211.3977366-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>