omxvideodec: downstream pool is not deactivated until decoder stop when it is not used

In negotiation phase, gstomxvideodec try use to downstream bufferpool in gst_omx_video_dec_decide_allocation(), and decided pool is activated in gst_video_decoder_negotiate_pool().

But activated pool is not deactivated until decoder stop if downstream bufferpool is not used. When gstomxvideodec use own bufferpool and not use downstream bufferpool, Shouldn't the downstream pool be deactivated?