vulkan/wsi: Free the event in x11_manage_fifo_queues().

Cc: mesa-stable@lists.freedesktop.org
Signed-off-by: Henri Verbeet <hverbeet@gmail.com>
Fixes: e73d136a02 ("vulkan/wsi/x11: Implement FIFO mode.")
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com

src/vulkan/wsi/wsi_common_x11.c

@@ -939,6 +939,7 @@ x11_manage_fifo_queues(void *state)
             goto fail;
 
          result = x11_handle_dri3_present_event(chain, (void *)event);
+         free(event);
          if (result != VK_SUCCESS)
             goto fail;
       }