Printf fixes.

Printf fixes.

Original commit message from CVS:
* gst/gstpad.c: (pre_activate):
* gst/gstregistry.c: (gst_registry_scan_path_level):
* gst/gstregistryxml.c: (load_plugin):
* libs/gst/controller/gstcontroller.c:
(gst_controlled_property_set_interpolation_mode):
* libs/gst/dataprotocol/dataprotocol.c:
(gst_dp_packet_from_event_1_0):
* libs/gst/net/gstnetclientclock.c:
(gst_net_client_clock_observe_times):
* plugins/elements/gstfdsrc.c: (gst_fd_src_create):
Printf fixes.