CVE-2026-64134 ALSA: pcm: Don't setup bogus iov_iter for silencing

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Don't setup bogus ioviter for silencing At transition to the ioviter for PCM data transfer, we blindly applied the ioviter setup also for silencing i.e. data = NULL, and it leads to a calculation of bogus ioviter...