cmake: fix using USE_LUAJIT

Author: ligurio

tests/capi/CMakeLists.txt

@@ -98,7 +98,7 @@ function(create_test)
   endif ()
   set(dict_path ${CORPUS_BASE_PATH}/${test_name}.dict)
   set(corpus_path ${CORPUS_BASE_PATH}/${test_prefix})
-  if(USE_LUAJIT)
+  if(IS_LUAJIT)
     set(corpus_path ${CORPUS_BASE_PATH}/${test_name})
   endif()
   if (EXISTS ${dict_path})