cgroup: allow adding self (PID 0) to a leaf group

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

src/cgroup.c

@@ -139,7 +139,7 @@ static int cgroup_leaf_init(char *group, char *name, int pid, const char *cfg)
 	char path[256];
 
 	_d("group %s, name %s, pid %d, cfg %s", group, name, pid, cfg ?: "NIL");
-	if (pid <= 1) {
+	if (pid < 0 || pid == 1) {
 		errno = EINVAL;
 		return 1;
 	}

src/getty.c

@@ -185,7 +185,7 @@ static int do_login(char *name)
 {
 	struct stat st;
 
-	cgroup_user(name, getpid());
+	cgroup_user(name, 0);
 	execl(_PATH_LOGIN, _PATH_LOGIN, name, NULL);
 
 	/*