Changes

core: fix printf format casts for struct timeval fields

Explicitly cast struct timeval fields to long when passing them to
printf-style functions.

This avoids compiler warnings/errors on platforms where tv_sec or
tv_usec are not exactly of type long, while keeping the existing log
and control output unchanged.

Change-Id: Icac9e392c728948a7976970658e37f5e0da41709