fixed missed arch renaming (from C.Bergstrom)

llvm-svn: 238153
diff --git a/openmp/runtime/cmake/HelperFunctions.cmake b/openmp/runtime/cmake/HelperFunctions.cmake
index a05eb56..b229223 100644
--- a/openmp/runtime/cmake/HelperFunctions.cmake
+++ b/openmp/runtime/cmake/HelperFunctions.cmake
@@ -63,7 +63,7 @@
         set(${return_arch_string} "Intel(R) 64" PARENT_SCOPE)
     elseif(${MIC})
         set(${return_arch_string} "Intel(R) Many Integrated Core Architecture" PARENT_SCOPE)
-    elseif(${arch} STREQUAL "l1")
+    elseif(${LIBOMP_ARCH} STREQUAL "l1")
         set(${return_arch_string} "L1OM" PARENT_SCOPE)
     elseif(${ARM})
         set(${return_arch_string} "ARM" PARENT_SCOPE)