drm/amd/display: attempt to fix the logic in commit_planes_for_stream()

The indentation is screwed up.  I'm not sure quite how the logic
should flow.  Someone more familiar with this code should
verify this.

Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>