gst/: Modifications for disapearance of GST_PAD_IS_USABLE()
Original commit message from CVS: * gst/dvdlpcmdec/gstdvdlpcmdec.c: (gst_dvdlpcmdec_chain_raw): * gst/realmedia/rmdemux.c: (gst_rmdemux_chain), (gst_rmdemux_add_stream), (gst_rmdemux_parse_mdpr), (gst_rmdemux_parse_packet): Modifications for disapearance of GST_PAD_IS_USABLE()