Update for _get_state() API change.

Update for _get_state() API change.

Original commit message from CVS:
* check/pipelines/simple_launch_lines.c: (run_pipeline):
* examples/seeking/Makefile.am:
* examples/seeking/cdplayer.c: (play_cb), (pause_cb), (stop_cb):
* examples/seeking/seek.c: (make_avi_msmpeg4v3_mp3_pipeline),
(do_seek), (set_update_scale), (message_received), (main):
* gst-libs/gst/audio/gstringbuffer.c: (gst_ring_buffer_commit),
(gst_ring_buffer_read), (gst_ring_buffer_clear):
Update for _get_state() API change.