egl/android: Remove our own reference to buffers.

We currently doesn't maintain it correctly and the buffer gets leaked if
surface is destroyed before calling swapping buffers.

From Android frameworks/native/libs/nativewindow/include/system/window.h:

  The window holds a reference to the buffer between dequeueBuffer and
  either queueBuffer or cancelBuffer, so clients only need their own
  reference if they might use the buffer after queueing or canceling it.

v2: Remove our own reference.

Fixes: 0212db3504 ("egl/android: Cancel any outstanding ANativeBuffer in surface destructor")

Reviewed-by: Chia-I Wu <olvaffe@gmail.com> (v1)
Reviewed-By: Tapani Pälli <tapani.palli@intel.com>
Signed-off-by: Lepton Wu <lepton@chromium.org>

src/egl/drivers/dri2/platform_android.c

@@ -240,8 +240,6 @@ droid_window_dequeue_buffer(struct dri2_egl_surface *dri2_surf)
         close(fence_fd);
    }
 
-   dri2_surf->buffer->common.incRef(&dri2_surf->buffer->common);
-
    /* Record all the buffers created by ANativeWindow and update back buffer
     * for updating buffer's age in swap_buffers.
     */
@@ -298,7 +296,6 @@ droid_window_enqueue_buffer(_EGLDisplay *disp, struct dri2_egl_surface *dri2_sur
    dri2_surf->window->queueBuffer(dri2_surf->window, dri2_surf->buffer,
                                   fence_fd);
 
-   dri2_surf->buffer->common.decRef(&dri2_surf->buffer->common);
    dri2_surf->buffer = NULL;
    dri2_surf->back = NULL;
 
@@ -321,6 +318,7 @@ droid_window_cancel_buffer(struct dri2_egl_surface *dri2_surf)
    dri2_surf->out_fence_fd = -1;
    ret = dri2_surf->window->cancelBuffer(dri2_surf->window,
                                          dri2_surf->buffer, fence_fd);
+   dri2_surf->buffer = NULL;
    if (ret < 0) {
       _eglLog(_EGL_WARNING, "ANativeWindow::cancelBuffer failed");
       dri2_surf->base.Lost = EGL_TRUE;