Fix _pad_get_direction wrt ghostpads.

Fix _pad_get_direction wrt ghostpads.

Original commit message from CVS:
* gst/gstpad.c: (gst_pad_get_direction),
(_gst_pad_default_fixate_foreach), (gst_pad_collectv),
(gst_pad_collect_valist):
* testsuite/bins/interface.c: (main):
* testsuite/caps/audioscale.c: (test_caps):
* testsuite/caps/caps.c: (test1), (test2), (test3):
* testsuite/caps/deserialize.c: (main):
* testsuite/caps/enumcaps.c: (main):
* testsuite/caps/filtercaps.c: (main):
* testsuite/caps/intersect2.c: (main):
* testsuite/caps/random.c: (main):
* testsuite/caps/renegotiate.c: (my_fixate), (main):
* testsuite/caps/sets.c: (check_caps):
* testsuite/caps/simplify.c: (check_caps), (main):
* testsuite/caps/subtract.c: (check_caps):
Fix _pad_get_direction wrt ghostpads.
Fix caps testsuite.