xfs/013: allow non-write fsstress operations in background workload

xfs/013: allow non-write fsstress operations in background workload

It has been reported that test xfs/013 probably uses more space than
necessary, exhausting space if run against a several GB sized ramdisk.
xfs/013 primarily creates, links and removes inodes. Most of the space
consumption occurs via the background fsstress workload.

Remove the fsstress -w option that suppresses non-write operations. This
slightly reduces the storage footprint while still providing a
background workload for the test.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>