tools: remove unused sysconfig variable XENSTORED_ROOTDIR
The sysconfig variable XENSTORED_ROOTDIR is not used anymore.
It used to point to a directory with tdb files, which is now a tmpfs.
In case the database is not in tmpfs, like on sysv and BSD systems,
xenstored will truncate existing database files during start.
Fixes: 2ef6ace428 ("tools: don't remove tdb data base file before starting xenstored")
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wl@xen.org>