xfs/167: adjust runtime with TIME_FACTOR

xfs/167: adjust runtime with TIME_FACTOR

xfs/167 takes between 6 and 10 minutes to run on my SSD based test
machines. It's running 50 loops of a unwritten extent conversion
test program whilst running a heavy fsstress workload in the
background. This does not need to run for 10 minutes on every auto
group regression test run. Shorten it to loop 5 * TIME_FACTOR
so that normal runtime drops to something sane but can still be
easily ramped up if soak/stress testing is being run.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Zorro Lang <zlang@kernel.org>