core: fix fd leak in exec_shared_runtime_deserialize_one

The userns/netns/ipcns fdpairs were declared as plain int arrays without
_cleanup_close_pair_. If exec_shared_runtime_add() fails (e.g. OOM on
hashmap_ensure_put), the already-opened fds are leaked.

Since exec_shared_runtime_add() uses TAKE_FD on success, the array
entries are reset to -1 after ownership transfer, so adding
_cleanup_close_pair_ is safe and closes the fds only when they were
never consumed.

Signed-off-by: dongshengyuan <dongshengyuan@uniontech.com>

src/core/execute.c

@@ -2748,7 +2748,8 @@ int exec_shared_runtime_deserialize_compat(Unit *u, const char *key, const char
 int exec_shared_runtime_deserialize_one(Manager *m, const char *value, FDSet *fds) {
         _cleanup_free_ char *tmp_dir = NULL, *var_tmp_dir = NULL;
         char *id = NULL;
-        int r, userns_fdpair[] = {-1, -1}, netns_fdpair[] = {-1, -1}, ipcns_fdpair[] = {-1, -1};
+        _cleanup_close_pair_ int userns_fdpair[] = EBADF_PAIR, netns_fdpair[] = EBADF_PAIR, ipcns_fdpair[] = EBADF_PAIR;
+        int r;
         const char *p, *v = ASSERT_PTR(value);
         size_t n;