LU-6788 build: Remove build/lbuild backwards compatibility symlink

LU-6788 build: Remove build/lbuild backwards compatibility symlink

Enough time has passed since lbuild was moved to contrib to remove
the symlink that we left behind in the build directory to accommodate
Intel's build farm.

Change-Id: I4d3b6038aad0663c3030590d161b6d71d05e6d43
Signed-off-by: Christopher J. Morrone <morrone2@llnl.gov>
Reviewed-on: http://review.whamcloud.com/15464
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Minh Diep <minh.diep@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>