libutils: get ride of debug trace file errors

put them as warning only...

Change-Id: Idbdddbc83833c938288da6b7a68fb3539d139538
Merge remote-tracking branch 'cyan/cm-10.1' into cm-10.1
Merge branch 'cm-10.1' of https://github.com/Quarx2k/android_frameworks_native into RootBox