lttng: Do not cache attribute tree locations

lttng: Do not cache attribute tree locations

As a requirement for partial histories, we cannot cache
commonly-used attribute tree locations in the state providers.
Since the partial history's inner state provider will not know
the cached values of the real one, we need to resolve them
every time.

This unfortunately hampers the performance of standard state
system constructions a bit.

Change-Id: I93e104ea1e4fe7159805ff54296d4cfc830444a3
Signed-off-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Reviewed-on: https://git.eclipse.org/r/10755
Tested-by: Hudson CI
Reviewed-by: Bernd Hufmann <bhufmann@gmail.com>
IP-Clean: Bernd Hufmann <bhufmann@gmail.com>
Tested-by: Bernd Hufmann <bhufmann@gmail.com>