drm/ast: Don't pin cursor source BO explicitly during update

Vmapping the cursor source BO contains an implicit pin operation,
so there's no need to do this manually.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209142527.26415-2-tzimmermann@suse.de

drivers/gpu/drm/ast/ast_cursor.c

@@ -180,12 +180,9 @@ int ast_cursor_blit(struct ast_private *ast, struct drm_framebuffer *fb)
 
 	gbo = drm_gem_vram_of_gem(fb->obj[0]);
 
-	ret = drm_gem_vram_pin(gbo, 0);
-	if (ret)
-		return ret;
 	ret = drm_gem_vram_vmap(gbo, &map);
 	if (ret)
-		goto err_drm_gem_vram_unpin;
+		return ret;
 	src = map.vaddr; /* TODO: Use mapping abstraction properly */
 
 	dst = ast->cursor.map[ast->cursor.next_index].vaddr_iomem;
@@ -194,13 +191,8 @@ int ast_cursor_blit(struct ast_private *ast, struct drm_framebuffer *fb)
 	update_cursor_image(dst, src, fb->width, fb->height);
 
 	drm_gem_vram_vunmap(gbo, &map);
-	drm_gem_vram_unpin(gbo);
 
 	return 0;
-
-err_drm_gem_vram_unpin:
-	drm_gem_vram_unpin(gbo);
-	return ret;
 }
 
 static void ast_cursor_set_base(struct ast_private *ast, u64 address)