Fix sample_multi_transcode intermittent segfault

HSD ID: 15012772965
Tested command: ./sample_multi_transcode -par config.par

Author: vcheah

CHANGELOG.md

@@ -10,6 +10,9 @@ portable media pipelines on CPUs, GPUs, and other accelerators.
 
 ## [Unreleased]
 
+### Fixed
+- Sample_multi_transcode intermittent segfault on wayland
+
 ### Removed 
 - USE_ONEAPI_INSTALL_LAYOUT build shortcut
 - '-sw' option from examples 

tools/legacy/sample_misc/wayland/src/class_wayland.cpp

@@ -152,8 +152,10 @@ void Wayland::FreeSurface() {
         while (!m_buffers_list.empty()) {
             wl_surface_attach(m_surface, NULL, 0, 0);
             wl_surface_commit(m_surface);
-            if (wl_display_dispatch_queue(m_display, m_event_queue) < 1)
+            if (wl_display_dispatch_queue(m_display, m_event_queue) < 1) {
+                DestroyBufferList();
                 break;
+            }
         }
 
         wl_surface_destroy(m_surface);