Tests: Clean RunCMake.UnityBuild cases

Tests/RunCMake/UnityBuild/RunCMakeTest.cmake

@@ -2,11 +2,9 @@ include(RunCMake)
 
 function(run_build name)
   set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/${name}-build)
-  set(RunCMake_TEST_NO_CLEAN 1)
   run_cmake(${name})
+  set(RunCMake_TEST_NO_CLEAN 1)
   run_cmake_command(${name}-build ${CMAKE_COMMAND} --build . --config Debug)
-  unset(RunCMake_TEST_BINARY_DIR)
-  unset(RunCMake_TEST_NO_CLEAN)
 endfunction()
 
 run_cmake(unitybuild_c)
@@ -30,12 +28,10 @@ run_build(unitybuild_anon_ns_group_mode)
 
 function(run_test name)
   set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/${name}-build)
-  set(RunCMake_TEST_NO_CLEAN 1)
   run_cmake(${name})
+  set(RunCMake_TEST_NO_CLEAN 1)
   run_cmake_command(${name}-build ${CMAKE_COMMAND} --build . --config Debug)
   run_cmake_command(${name}-test ${CMAKE_CTEST_COMMAND} -C Debug)
-  unset(RunCMake_TEST_BINARY_DIR)
-  unset(RunCMake_TEST_NO_CLEAN)
 endfunction()
 
 run_test(unitybuild_runtest)