Correct some bad logic in the ModelToMesh2D Unit Test.

Status Job ID Name Coverage
  External
passed cdash

passed kwrobot-branch-check

passed smtk-endor-linux-shared-relwithdebinfo

passed smtk-endor-linux-shared-relwithdebinfo

passed smtk-endor-linux-shared-relwithdebinfo

passed smtk-endor-linux-shared-relwithdebinfo

passed smtk-endor-linux-shared-relwithdebinfo

passed smtk-endor-linux-shared-relwithdebinfo

00:05:16