CRAS: Refactor audio_debug_info related functions

In cras_test_client, we'll need to use some code in those for printing
audio_debug_info when printing snapshot information.

BUG=chromium:866240
TEST=Check if
     $ cras_test_client --dump_a
     works well.
TEST=Apply full patch set to run
     $ cras_test_client --playback_file /dev/zero --playback_delay_us
     10000
     and input 'i' and 'key_enter' to cause underrun event. Then using
     $ cras_test_client --dump_e"
     could see the audio thread snapshot for that event.

Change-Id: If7f30103ebe9913b635dbf460f940acbf4c40deb
Reviewed-on: https://chromium-review.googlesource.com/1148085
Commit-Ready: Chih-Yang Hsia <paulhsia@chromium.org>
Tested-by: Chih-Yang Hsia <paulhsia@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
1 file changed