ext/jack/gstjackaudiosink.c: Try t better name clients. properly handle return codes when re- establishing links.

Original commit message from CVS:
* ext/jack/gstjackaudiosink.c: (gst_jack_ring_buffer_open_device),
(gst_jack_ring_buffer_acquire):
Try t better name clients. properly handle return codes when re-
establishing links.