liburingutils: Check for return code for set_iowait API

set_iowait disables the iowait. Check the return code
and return false if the kernel doesn't support the feature.

Bug: 500036633
Test: Boot the device and verify the API settings.
Signed-off-by: Akilesh Kailash <akailash@google.com>
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:3e9f450cb8492c9ff975a6aee0f065e8a4aa8f6c
Merged-In: I19d31c5eb05f8bd793fc2ec0183128c4110553f7
Change-Id: I19d31c5eb05f8bd793fc2ec0183128c4110553f7