setup-environment-internal: fix issue left over from dedicated build folder commit
setup-environment-internal: fix issue left over from dedicated build folder commit

This bug is introduced in commit "setup-environment-internal: use a dedicated
build folder", the symlink for the manifest is no longer created properly.

Change-Id: Ia700023613e26e51dd9765513ef5e1be246d6607
Signed-off-by: Nicolas Dechesne <05fca36dfcf68f7e1c9eaf62b074676ab50a133b@linaro.org>

linaro-home/lhg-oe-manifests,96boards/oe-rpb-manifest,ndechesne/qcom-oe-manifest