Fix page_cache leak in cache_resize

Signed-off-by: Orit Wasserman <owasserm@redhat.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>

page_cache.c

@@ -208,6 +208,7 @@ int64_t cache_resize(PageCache *cache, int64_t new_num_pages)
         }
     }
 
+    g_free(cache->page_cache);
     cache->page_cache = new_cache->page_cache;
     cache->max_num_items = new_cache->max_num_items;
     cache->num_items = new_cache->num_items;