LU-1199 build: Relocate missed lbuild-fc18

lbuild-fc18 was missed in the move of the other lbuild files
to contrib/lbuild.  This relocates that file as well.

Change-Id: I2775f1e0aa4c7d17d2e1d8a114f2bea3702fec68
Signed-off-by: Christopher J. Morrone <morrone2@llnl.gov>
Reviewed-on: http://review.whamcloud.com/5872


Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>