ALSA: control: Fix unannotated kfree() cleanup

The recent conversion to the automatic kfree() forgot to mark a
variable with __free(kfree), leading to memory leaks.  Fix it.

Fixes: 1052d988 ("ALSA: control: Use automatic cleanup of kfree()")
Reported-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
Closes: https://lore.kernel.org/r/c1e2ef3c-164f-4840-9b1c-f7ca07ca422a@alu.unizg.hr


Message-ID: <20240320062722.31325-1-tiwai@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>