Remove hard-coded llvm-project folder for rocrtst

Signed-off-by: Wang, Yanyao <yanyao.wang@amd.com>
Change-Id: I9ba81c1182da812596d7d314f3a6dae7cbcd0c2d

rocrtst/suites/test_common/CMakeLists.txt

@@ -152,8 +152,8 @@ else()
 endif()
 
 if(NOT EXISTS "${OPENCL_INC_DIR}/opencl-c.h")
-  if(DEFINED ENV{WORK_ROOT})
-    set(OPENCL_INC_DIR "$ENV{WORK_ROOT}/external/llvm-project/clang/lib/Headers/")
+  if(DEFINED ENV{LLVM_PROJECT_ROOT})
+    set(OPENCL_INC_DIR "$ENV{LLVM_PROJECT_ROOT}/clang/lib/Headers/")
   else()
     set(OPENCL_INC_DIR "${OPENCL_DIR}/../../../external/llvm-project/clang/lib/Headers/")
   endif()