LU-14725 tests: sanity/27Q to remove own symlink in /tmp

otherwise any subsequent restart of MDS/MGS on a local setup
with ZFS backend gets stuck as zpool import scans /tmp and
stat's every found file.

Test-Parameters: trivial
Fixes: cd4caef54f ("LU-14583 llapi: handle symlinks in llapi_file_get_stripe()")
Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I2eb4cb8819670acef0302e1fe5ab767be7f46842
Reviewed-on: https://review.whamcloud.com/43875
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>