attach: fix return value & cleanups

src/lxc/start.c

@@ -868,12 +868,16 @@ int lxc_init(const char *name, struct lxc_handler *handler)
 
 out_delete_terminal:
 	lxc_terminal_delete(&handler->conf->console);
+
 out_restore_sigmask:
 	(void)pthread_sigmask(SIG_SETMASK, &handler->oldmask, NULL);
+
 out_delete_tty:
 	lxc_delete_tty(&conf->ttys);
+
 out_aborting:
 	(void)lxc_set_state(name, handler, ABORTING);
+
 out_close_maincmd_fd:
 	lxc_abstract_unix_close(conf->maincmd_fd);
 	conf->maincmd_fd = -1;

src/lxc/utils.c

@@ -2038,9 +2038,10 @@ int lxc_preserve_ns(const int pid, const char *ns)
 	ret = snprintf(path, __NS_PATH_LEN, "/proc/%d/ns%s%s", pid,
 		       !ns || strcmp(ns, "") == 0 ? "" : "/",
 		       !ns || strcmp(ns, "") == 0 ? "" : ns);
-	errno = EFBIG;
-	if (ret < 0 || (size_t)ret >= __NS_PATH_LEN)
-		return -EFBIG;
+	if (ret < 0 || (size_t)ret >= __NS_PATH_LEN) {
+		errno = EFBIG;
+		return -1;
+	}
 
 	return open(path, O_RDONLY | O_CLOEXEC);
 }