CRAS: remove non-critical logs in libcras and cras_util

Remove non-critial logs in libcras and cras_utils.
Only logs when important call fails.
Fix the return code checking in cras_set_thread_priority.

BUG=chromium:705124
TEST=check there is no redundant logs about server_fd_state.
TEST=check there is message warning that schedparam call fails on board
that does not allow realtime priority (because rt-limit is not set yet)

Change-Id: I4a182001fb661e42bcbc22104b354fc01a81eaa5
Reviewed-on: https://chromium-review.googlesource.com/461699
Commit-Ready: Cheng-Yi Chiang <cychiang@chromium.org>
Tested-by: Cheng-Yi Chiang <cychiang@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
2 files changed