Revert "Revert "ALSA: pcm: Fix races among concurrent prealloc proc writes""

This reverts commit 07566786.

It fixes CVE-2022-1048 and it had to originally be reverted due to ABI
issues.  Add it back now as the ABI "break" is allowed and we want to
fix this real problem.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I2989057ebdab8269c2f98702a9afb01d4814285b