On slower machines, startup can take some time,
set last values to current [us]time before actual test.

This caused test to fail, because first delta contained
time spent by test starting up:
getrusage04    0  TINFO  :  utime:         999us; stime:        6998us
getrusage04    0  TINFO  :  utime:         999us; stime:        6998us
getrusage04    1  TFAIL  :  stime increased > 1000us: delta = 6998us

Signed-off-by: Jan Stancek <jstancek@redhat.com>
---
  testcases/kernel/syscalls/getrusage/getrusage04.c |    4 +++-
  1 files changed, 3 insertions(+), 1 deletions(-)