gst/gstbin.c: use gst_object_has_ancestor().

gst/gstbin.c: use gst_object_has_ancestor().

Original commit message from CVS:
* gst/gstbin.c: (bin_element_is_semi_sink), (gst_bin_change_state):
use gst_object_has_ancestor().

* gst/gstobject.c: (gst_object_has_ancestor):
* gst/gstobject.h:
gst_object_has_ancestor() copied from gstbin.c as it is a
usefull function.

* tests/instantiate/create.c: (create_all_elements):
* tests/lat.c: (handoff_src), (handoff_sink):
* tests/sched/runxml.c: (main):
* tests/seeking/seeking1.c: (main):
* tests/threadstate/threadstate2.c: (bus_handler), (timeout_func),
(main):
Fix compilation of some tests.