Namespace private ABI lttng_transport_find symbol

The major SONAME bump to '1' gives us the opportunity to properly
namespace public symbols. This symbol is part of the ABI between
liblttng-ust-ctl and liblltng-ust and is not part of the public API.

Change-Id: Ibdb33aff98f7b974fac3c28889718851286ce2f9
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>