Fix: baddr_statedump tracepoint registration

Fix: baddr_statedump tracepoint registration

Ensure baddr_statedump tracepoint registration is completed prior to
using the tracepoint in lttng_ust_baddr_statedump().

Make liblttng-ust-dl robust for explicit baddr_statedump tracepoint
deregistration in lttng_ust_cleanup() (prevent dlopen/dlclose to get
traced if ust_baddr tracepoints are not available).

Signed-off-by: Paul Woegerer <paul_woegerer@mentor.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>