gst/elements/gsttypefindelement.c: Use gst_pad_use_explicit_caps for src pad.

gst/elements/gsttypefindelement.c: Use gst_pad_use_explicit_caps for src pad.

Original commit message from CVS:
* gst/elements/gsttypefindelement.c:
(gst_type_find_element_have_type), (gst_type_find_element_init):
Use gst_pad_use_explicit_caps for src pad.
* gst/gstpad.c: (gst_pad_try_set_caps):  Check that link exists
before using it.