framebuffer_update_jpeg_buffer was previously bugged as it always
updated the jpeg buffer from the frame buffer versus the image
object it was attached to. e.g. img.flush() always flushed the
frame buffer and not the image object it was called on.
Detection flag should be set after CSIs are detected in
the scanning code, and functions that loop over CSIs
should check it.
Signed-off-by: iabdalkader <i.abdalkader@gmail.com>