Build: fix typo in filename.

test/CMakeLists.txt

@@ -96,7 +96,7 @@ SET( TEST_SRCS
   unit/utScenePreprocessor.cpp
   unit/utSharedPPData.cpp
   unit/utStringUtils.cpp
-  unit/utSMLImiportExport.cpp
+  unit/utSMDImportExport.cpp
   unit/utSortByPType.cpp
   unit/utSplitLargeMeshes.cpp
   unit/utTargetAnimation.cpp