initctl: skip cgroup in status output pid_cgruop() fails

In some (error) cases the PID known to Finit may no longer exist, or may
not have been added to a cgroup (yet).  Handle this case by skipping the
output of cgroup info in such conditions.

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

src/initctl.c

@@ -831,6 +831,8 @@ static int show_status(char *arg)
 			char *group;
 
 			group = pid_cgroup(svc->pid, grbuf, sizeof(grbuf));
+			if (!group)
+				goto no_cgroup; /* ... or PID doesn't exist (anymore) */
 			snprintf(path, sizeof(path), "%s/%s", FINIT_CGPATH, group);
 			cg = cg_conf(path);
 
@@ -840,6 +842,7 @@ static int show_status(char *arg)
 			       cg->cg_mem.min, cg->cg_mem.max);
 			show_cgroup_tree(group, "              ");
 		}
+	no_cgroup:
 		printf("\n");
 
 		return do_log(svc->cmd);