qxl: No need for NULL check before calling qxl_bo_unref()

qxl_bo_unref() is already performing a NULL check.
Signed-off-by: Christophe Fergeau <cfergeau@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20181120162004.22807-1-cfergeau@redhat.comSigned-off-by: Gerd Hoffmann <kraxel@redhat.com>

drivers/gpu/drm/qxl/qxl_display.c

@@ -670,9 +670,7 @@ static void qxl_cursor_atomic_update(struct drm_plane *plane,
 	qxl_push_cursor_ring_release(qdev, release, QXL_CMD_CURSOR, false);
 	qxl_release_fence_buffer_objects(release);
 
-	if (old_cursor_bo)
-		qxl_bo_unref(&old_cursor_bo);
-
+	qxl_bo_unref(&old_cursor_bo);
 	qxl_bo_unref(&cursor_bo);
 
 	return;

drivers/gpu/drm/qxl/qxl_draw.c

@@ -247,8 +247,7 @@ void qxl_draw_opaque_fb(const struct qxl_fb_image *qxl_fb_image,
 	qxl_release_fence_buffer_objects(release);
 
 out_free_palette:
-	if (palette_bo)
-		qxl_bo_unref(&palette_bo);
+	qxl_bo_unref(&palette_bo);
 out_free_image:
 	qxl_image_free_objects(qdev, dimage);
 out_free_drawable:

drivers/gpu/drm/qxl/qxl_kms.c

@@ -313,10 +313,8 @@ int qxl_device_init(struct qxl_device *qdev,
 
 void qxl_device_fini(struct qxl_device *qdev)
 {
-	if (qdev->current_release_bo[0])
-		qxl_bo_unref(&qdev->current_release_bo[0]);
-	if (qdev->current_release_bo[1])
-		qxl_bo_unref(&qdev->current_release_bo[1]);
+	qxl_bo_unref(&qdev->current_release_bo[0]);
+	qxl_bo_unref(&qdev->current_release_bo[1]);
 	flush_work(&qdev->gc_work);
 	qxl_ring_free(qdev->command_ring);
 	qxl_ring_free(qdev->cursor_ring);