Apply 'cputime: Avoid multiplication overflow on utime scaling' to  task_times
- since scale_utime is no longer a part of the picture (at least not like before), we need to use scale_stime since it reduces overflow on workloads
Signed-off-by: Luis Cruz <ljc2491@gmail.com>
sched: ensure stime is initialized
- fixes "warning: 'stime' may be used uninitialized in this function"
Signed-off-by: Luis Cruz <ljc2491@gmail.com>