server: Handle NULL thread in send_hardware_message (Coverity).
diff --git a/server/queue.c b/server/queue.c
index ab524a7..bc0aea7 100644
--- a/server/queue.c
+++ b/server/queue.c
@@ -1720,7 +1720,7 @@
 
     if (!(data = mem_alloc( sizeof(*data) )))
     {
-        release_object( thread );
+        if (thread) release_object( thread );
         return;
     }
     memset( data, 0, sizeof(*data) );