Change the scanout buffer for tearfree when set_mode_major
In some case, CRTC is enabled when call drmmode_set_mode_major(), so drmmode_crtc_scanout_update() will update the buffer that is being scanned, This will cause the screen blurred and flickering.
So Change the scanout buffer for tearfree when set_mode_major.
Signed-off-by: Shixiong Ou oushixiong@kylinos.cn