ALSA: emu10k1: drop redundant snd_emu10k1_efx_playback_hw_free()

Or actually, replace snd_emu10k1_playback_hw_free() with it, as that is
a subset.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230421141006.1005452-1-oswald.buddenhagen@gmx.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>