drm/vc4: use simpler remove_conflicting_framebuffers(NULL)

Use remove_conflicting_framebuffers(NULL) instead of open-coding it.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Eric Anholt <eric@anholt.net>
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/be7e6396e6e7159695a5bccc109c6ab49a51e0d8.1535810304.git.mirq-linux@rere.qmqm.pl

drivers/gpu/drm/vc4/vc4_drv.c

@@ -248,24 +248,6 @@ static void vc4_match_add_drivers(struct device *dev,
 	}
 }
 
-static void vc4_kick_out_firmware_fb(void)
-{
-	struct apertures_struct *ap;
-
-	ap = alloc_apertures(1);
-	if (!ap)
-		return;
-
-	/* Since VC4 is a UMA device, the simplefb node may have been
-	 * located anywhere in memory.
-	 */
-	ap->ranges[0].base = 0;
-	ap->ranges[0].size = ~0;
-
-	drm_fb_helper_remove_conflicting_framebuffers(ap, "vc4drmfb", false);
-	kfree(ap);
-}
-
 static int vc4_drm_bind(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
@@ -298,7 +280,7 @@ static int vc4_drm_bind(struct device *dev)
 	if (ret)
 		goto gem_destroy;
 
-	vc4_kick_out_firmware_fb();
+	drm_fb_helper_remove_conflicting_framebuffers(NULL, "vc4drmfb", false);
 
 	ret = drm_dev_register(drm, 0);
 	if (ret < 0)