rtsp-thread-pool.c: fix clang 10 warning

clang 10 is complaining about incompatible types due to the
glib typesystem.

```
../subprojects/gst-rtsp-server/gst/rtsp-server/rtsp-thread-pool.c:534:10: error: incompatible pointer types passing 'typeof ((((void *)0))) *' (aka 'void **') to parameter of type 'GThreadPool **' (aka 'struct _GThreadPool **') [-Werror,-Wincompatible-pointer-types]
```

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-rtsp-server/-/merge_requests/145>

diff --git a/gst/rtsp-server/rtsp-thread-pool.c b/gst/rtsp-server/rtsp-thread-pool.c
index 6c53a01..7bfee10 100644 (file)
--- a/gst/rtsp-server/rtsp-thread-pool.c
+++ b/gst/rtsp-server/rtsp-thread-pool.c
@@ -531,7 +531,7 @@ gst_rtsp_thread_pool_get_thread (GstRTSPThreadPool * pool,
   if (G_UNLIKELY (!g_atomic_pointer_get (&klass->pool))) {
     GThreadPool *t_pool;
     t_pool = g_thread_pool_new ((GFunc) do_loop, klass, -1, FALSE, NULL);
-    if (!g_atomic_pointer_compare_and_exchange (&klass->pool, NULL, t_pool))
+    if (!g_atomic_pointer_compare_and_exchange (&klass->pool, (GThreadPool *) NULL, t_pool))
       g_thread_pool_free (t_pool, FALSE, TRUE);
   }