compat_ioctl: remove translation for sound ioctls

The SNDCTL_* and SOUND_* commands are the old OSS user interface.

I checked all the sound ioctl commands listed in fs/compat_ioctl.c
to see if we still need the translation handlers. Here is what I
found:

- sound/oss/ is (almost) gone from the kernel, this is what actually
  needed all the translations
- The ALSA emulation for OSS correctly handles all compat_ioctl
  commands already.
- sound/oss/dmasound/ is the last holdout of the original OSS code,
  this is only used on arch/m68k, which has no 64-bit mode and
  hence needs no compat handlers
- arch/um/drivers/hostaudio_kern.c may run in 64-bit mode with
  32-bit x86 user space underneath it. This rare corner case is
  the only one that still needs the compat handlers.

By adding a simple redirect of .compat_ioctl to .unlocked_ioctl in the
UML driver, we can remove all the COMPATIBLE_IOCTL() annotations without
a change in functionality. For completeness, I'm adding the same thing
to the dmasound file, knowing that it makes no difference.

The compat_ioctl list contains one comment about SNDCTL_DSP_MAPINBUF and
SNDCTL_DSP_MAPOUTBUF, which actually would need a translation handler
if implemented. However, the native implementation just returns -EINVAL,
so we don't care.

Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>