r_submix: Fix logspam on pipe corruption

Prevent logging an error message on every attempt to write
if the FIFO backing up the MonoPipe got corrupted. This condition
can be detected by checking for -EIO error code.

Bug: 74067530
Test: make audio_utils_fifo_base::mIsShutdown to be set by default,
      run r_submix_tests and observe logcat

Change-Id: I5d67997e902e834f04c10f9ffb39b16cba9c5739
1 file changed