ALSA: emu10k1: simplify interrupt handler, part 1

IPR_CHANNELNUMBERMASK cannot be non-zero when IPR_CHANNELLOOP is unset,
so join marking them as handled.
This logically reverts part of commit f453e20d8a0 ("ALSA update
0.9.3a"), which made the inverse change with no explanation.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230518093047.3697887-1-oswald.buddenhagen@gmx.de


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