test: fix target-run-simple-swift

The parameterized version of `target-run-simple-swift` has a
capture group substitution in this macro.  Ensure that it is substituted
correctly.

Author: compnerd

test/lit.cfg

@@ -1150,12 +1150,13 @@ config.substitutions.append(('%sftp-server',
 
 
 if not getattr(config, 'target_run_simple_swift', None):
-    config.target_run_simple_swift_parameterized = (
-        '%%empty-directory(%%t) && '
-        '%s %s %%s \\1 -o %%t/a.out -module-name main && '
-        '%s %%t/a.out &&'
-        '%s %%t/a.out'
-        % (config.target_build_swift, mcp_opt, config.target_codesign, config.target_run))
+    config.target_run_simple_swift_parameterized =                               \
+        (SubstituteCaptures('%%empty-directory(%%t) && '
+                            '%s %s %%s \\1 -o %%t/a.out -module-name main && '
+                            '%s %%t/a.out &&'
+                            '%s %%t/a.out' % (config.target_build_swift,
+                                              mcp_opt, config.target_codesign,
+                                              config.target_run)))
     config.target_run_simple_swift = (
         '%%empty-directory(%%t) && '
         '%s %s %%s -o %%t/a.out -module-name main && '