tools: Fix install.sh for systemd

On a fedora system, if you run `sudo sh install.sh` you break your
system. The installation clobbers /var/run, a symlink to /run.
A subsequent boot fails when /var/run and /run are different since
accesses through /var/run can't find items that now only exist in /run
and vice-versa.

Skip populating /var/run/xen during make install.
The directory is already created by some scripts. Adjust all remaining
scripts to create XEN_RUN_DIR at runtime.

Use the shell variable XEN_RUN_DIR instead of hardcoded paths.

XEN_RUN_STORED is covered by XEN_RUN_DIR because xenstored is usually
started afterwards.

Reported-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>

tools/hotplug/NetBSD/rc.d/xendriverdomain.in

@@ -23,7 +23,7 @@ XLDEVD_PIDFILE="@XEN_RUN_DIR@/xldevd.pid"
 
 xendriverdomain_precmd()
 {
-	:
+	mkdir -p "${XEN_RUN_DIR}"
 }
 
 xendriverdomain_startcmd()