logind: always use 64bit session IDs

it's a bit confusing that on 32bit systems we'd risk session IDs
overruns like this. Let's expose the same behaviour everywhere and stick
to 64bit ids.

Since we format the ids as strings anyway this doesn't really change
anything performance-wise, it just pushes out collisions by overrun to
basically never happen.

src/login/logind-dbus.c

@@ -867,7 +867,7 @@ static int method_create_session(sd_bus_message *message, void *userdata, sd_bus
                 do {
                         id = mfree(id);
 
-                        if (asprintf(&id, "c%lu", ++m->session_counter) < 0)
+                        if (asprintf(&id, "c%" PRIu64, ++m->session_counter) < 0)
                                 return -ENOMEM;
 
                 } while (hashmap_contains(m->sessions, id));
@@ -3274,7 +3274,7 @@ static int method_inhibit(sd_bus_message *message, void *userdata, sd_bus_error
         do {
                 id = mfree(id);
 
-                if (asprintf(&id, "%lu", ++m->inhibit_counter) < 0)
+                if (asprintf(&id, "%" PRIu64, ++m->inhibit_counter) < 0)
                         return -ENOMEM;
 
         } while (hashmap_get(m->inhibitors, id));

src/login/logind.h

@@ -59,8 +59,8 @@ struct Manager {
         char **kill_only_users, **kill_exclude_users;
         bool kill_user_processes;
 
-        unsigned long session_counter;
-        unsigned long inhibit_counter;
+        uint64_t session_counter;
+        uint64_t inhibit_counter;
 
         Hashmap *session_units;
         Hashmap *user_units;