plugins: bootmisc: use relative symlink for /var/run

In an upside world, much like the Finit test cases, the root may be
relocated.  This make /var/run relative to /var, instead of /.  Which
hopefully is safer and covers more use-cases.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

plugins/bootmisc.c

@@ -135,7 +135,7 @@ static void setup(void *arg)
 		ln("/dev/shm", "/run/shm");
 
 		/* compat only, should really be set up by OS/dist */
-		ln("/run", "/var/run");
+		ln("../run", "/var/run");
 	} else {
 		makedir("/var/lock", 1777);
 		makedir("/var/run", 0755);