In the previous version, only certain buffers in the macroblockd were saved and
the restored. In this version, all of the buffers are saved and restored. The
code was then rolled into a loop for readability.

Also contains a tiny fix for when the -DOUTPUT_YUV_DENOISED flag is used.

Change-Id: Id925ef8b3fa122ae88acfa1d9a1e4df45df83518