lit.cfg: unbreak check-swift-*-only_non_executable-* test configuration

Author: gribozavr

test/lit.cfg

@@ -531,7 +531,7 @@ if run_vendor == 'apple':
         (config.variant_triple, stdlib_resource_dir_opt, mcp_opt))
     target_options_for_mock_sdk_after = sdk_overlay_dir_opt
 
-    if 'arm' in run_cpu and swift_test_mode != 'non_executable':
+    if 'arm' in run_cpu and swift_test_mode != 'only_non_executable':
         raise RuntimeError('Device tests are not currently supported.')
 
     if 'arm' in run_cpu: