getrusage: RUSAGE_THREAD should return ru_utime and ru_stime

getrusage: RUSAGE_THREAD should return ru_utime and ru_stime

commit 8916edef5888c5d8fe283714416a9ca95b4c3431 upstream.

Impact: task stats regression fix

Original getrusage(RUSAGE_THREAD) implementation can return ru_utime and
ru_stime. But commit "f06febc: timers: fix itimer/many thread hang" broke it.

this patch restores it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>