xfstests: fix _link_out_file callers

xfstests: fix _link_out_file callers

Currently the callers pass $seq, rather than the full path to the
test. As a result, it creates the link in the top level directory
and it points nowhere.  Fix it to create the link in the correct
place.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Rich Johnston <rjohnston@sgi.com>