gst/gsttypefindfactory.c: Don't unref factories after calling them.

gst/gsttypefindfactory.c: Don't unref factories after calling them.

Original commit message from CVS:
* gst/gsttypefindfactory.c: (gst_type_find_factory_call_function):
Don't unref factories after calling them.
* libs/gst/base/gsttypefindhelper.c: (gst_type_find_helper):
* plugins/elements/gsttypefindelement.c:
(gst_type_find_element_chain):
Free lists of factories after using them. Fixing typefinding memory
leaks.