dump: fix memory_mapping_filter leak

Spotted by ASAN.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

memory_mapping.c

@@ -337,6 +337,7 @@ void memory_mapping_filter(MemoryMappingList *list, int64_t begin,
         if (cur->phys_addr >= begin + length ||
             cur->phys_addr + cur->length <= begin) {
             QTAILQ_REMOVE(&list->head, cur, next);
+            g_free(cur);
             list->num--;
             continue;
         }