Do not try to mount /sys/fs/cgroup

It makes a mess when somebody else is already managing the cgroups.

cgroup.c

@@ -26,20 +26,9 @@ cgroup_setup(const char *chier, const char *controllers)
 	if (access(chierdir, F_OK) >= 0)
 		return 0;
 
-	if (mount("none", cgroupfs, "tmpfs", 0, NULL) < 0) {
-		cgroup_perror(cgroupfs);
-		return -1;
-	}
-	if (mkdir(chierdir, 0777) < 0) {
 	cgroup_perror(chierdir);
 	return -1;
 }
-	if (mount("none", chierdir, "cgroup", 0, controllers) < 0) {
-		cgroup_perror(chierdir);
-		return -1;
-	}
-	return 1;
-}
 
 int
 cgroup_create(const char *chier, const char *cgroup)