drm/sun4i: use simpler remove_conflicting_framebuffers(NULL)

Use remove_conflicting_framebuffers(NULL) instead of duplicating it.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/7d6d5bc4deac322b1351533c989cb3583e91be49.1535810304.git.mirq-linux@rere.qmqm.pl

drivers/gpu/drm/sun4i/sun4i_drv.c

@@ -61,22 +61,6 @@ static struct drm_driver sun4i_drv_driver = {
 	/* Frame Buffer Operations */
 };
 
-static void sun4i_remove_framebuffers(void)
-{
-	struct apertures_struct *ap;
-
-	ap = alloc_apertures(1);
-	if (!ap)
-		return;
-
-	/* The framebuffer can be located anywhere in RAM */
-	ap->ranges[0].base = 0;
-	ap->ranges[0].size = ~0;
-
-	drm_fb_helper_remove_conflicting_framebuffers(ap, "sun4i-drm-fb", false);
-	kfree(ap);
-}
-
 static int sun4i_drv_bind(struct device *dev)
 {
 	struct drm_device *drm;
@@ -119,7 +103,7 @@ static int sun4i_drv_bind(struct device *dev)
 	drm->irq_enabled = true;
 
 	/* Remove early framebuffers (ie. simplefb) */
-	sun4i_remove_framebuffers();
+	drm_fb_helper_remove_conflicting_framebuffers(NULL, "sun4i-drm-fb", false);
 
 	/* Create our framebuffer */
 	ret = sun4i_framebuffer_init(drm);