update var name in FindOMPL.cmake
update var name in FindOMPL.cmake

--HG--
extra : convert_revision : 3fcfb5bfbdb24f297b8cecf92979c59a06e37c3f

sonny-tarbouriech/ompl,florianhauer/ompl,sonny-tarbouriech/ompl,jvgomez/ompl,jvgomez/ompl,florianhauer/ompl,sonny-tarbouriech/ompl,florianhauer/ompl,davetcoleman/ompl,utiasASRL/batch-informed-trees,utiasASRL/batch-informed-trees,jvgomez/ompl,utiasASRL/batch-informed-trees,davetcoleman/ompl,davetcoleman/ompl,utiasASRL/batch-informed-trees,davetcoleman/ompl,jvgomez/ompl,davetcoleman/ompl,jvgomez/ompl,sonny-tarbouriech/ompl,florianhauer/ompl,florianhauer/ompl,davetcoleman/ompl,utiasASRL/batch-informed-trees,utiasASRL/batch-informed-trees,sonny-tarbouriech/ompl,sonny-tarbouriech/ompl,florianhauer/ompl,jvgomez/ompl