Make sure we're not scanning out any fbs with fancy modifiers when we try to light up new displays. This is already the case in cases where the screen gets resized, but in cases where that doesn't happen it might be possible for the modeset(s) to fail due to watermark/etc. constraints imposed by the fancy modifiers. We can avoid that by making sure everything gets unflipped before the modeset.
Signed-off-by: Ville Syrjälä email@example.com