gst/: Misc. fixes for problems discovered by Forte (different return types in functio...

gst/: Misc. fixes for problems discovered by Forte (different return types in function declaration and definition, po...

Original commit message from CVS:
Patch by: Josep Torra Valles  <josep at fluendo com>
* gst/iec958/ac3_padder.c: (ac3p_init):
* gst/mpegstream/gstmpegparse.c:
* gst/realmedia/rmdemux.c: (gst_rmdemux_parse__rmf),
(gst_rmdemux_parse_prop), (gst_rmdemux_parse_mdpr),
(gst_rmdemux_parse_indx), (gst_rmdemux_parse_indx_data),
(gst_rmdemux_parse_data), (gst_rmdemux_parse_cont),
(gst_rmdemux_parse_packet):
Misc. fixes for problems discovered by Forte (different return types
in function declaration and definition, pointer arithmetics with
void pointers). Fixes #362639.