Fix CMake syntax error

Change-Id: I8a39e50a741a23da3640fe7ccbcd83c844bf0d69

diff --git a/cmake/ThreadMPI.cmake b/cmake/ThreadMPI.cmake
index 53c6719d477c09073e8d7e43a7fdeb9b3b034955..244c5ac87138c7f7b745b1c3071ebf891eb2ca8f 100644 (file)
--- a/cmake/ThreadMPI.cmake
+++ b/cmake/ThreadMPI.cmake
@@ -37,7 +37,7 @@ include(CheckIncludeFiles)
 include(CheckFunctionExists)
 include(CheckCSourceCompiles)
 
-# sets TMPI_ATOMICS to 1 if atomic operations are found, undef otherwise
+# sets TMPI_ATOMICS to 1 if atomic operations are found, unset otherwise
 # Options:
 # include directory for thread_mpi/atomic.h
 MACRO(TMPI_TEST_ATOMICS INCDIR)
@@ -55,7 +55,7 @@ MACRO(TMPI_TEST_ATOMICS INCDIR)
             set(TMPI_ATOMICS_INCDIR ${INCDIR} CACHE INTERNAL "Atomic operations check include dir")
         else (TEST_ATOMICS)
             message(STATUS "Atomic operations not found")
-            undef(TEST_ATOMICS)
+            unset(TEST_ATOMICS)
         endif(TEST_ATOMICS)
     endif(NOT DEFINED TMPI_ATOMICS)
 ENDMACRO(TMPI_TEST_ATOMICS VARIABLE)