ignore symlink creation failure error

cmake/CheckFileSystemSymlinkSupport.cmake

@@ -4,6 +4,7 @@ execute_process(
   COMMAND ${CMAKE_COMMAND} -E create_symlink CMakeLists.txt "${CMAKE_CURRENT_BINARY_DIR}/TestingIfSymlinkWorks"
     WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
     RESULT_VARIABLE FILESYSTEM_LACKS_SYMLINKS
+    ERROR_QUIET
 )
 If (FILESYSTEM_LACKS_SYMLINKS)
   message(STATUS "Testing if file system supports symlinks -- unsupported")