util: Use clock_gettime instead of gettimeofday to be more precise

POSIX.1-2008 marks gettimeofday() as obsolete, recommending
the use of clock_gettime(2) instead.

Change-Id: I8d748c89f8c61e1285cedd1391b77eca7e20ffe0
Reviewed-on: https://code-review.googlesource.com/3090
Reviewed-by: Paul Wankadia <junyer@google.com>
2 files changed