Refactor variable naming in thread safety test

Renamed the variable $result to $res in test loop for clarity and consistency with the rest of the code. This change ensures uniformity in variable names and improves readability without altering the test's logic or output. The redundant PHP closing tag was also removed to align with PSR-2 coding standards.

tests/008-rayaop-thread-safety.phpt

@@ -31,12 +31,12 @@ class TestClass {
 method_intercept_init();
 
 for ($i = 0; $i < 3; $i++) {
-    $result = method_intercept(
+    $res = method_intercept(
         TestClass::class,
         'method',
         new SafetyTestInterceptor($i)
     );
-    echo "<Interceptor {$i} registered: " . ($result ? 'true' : 'false') . ">" . PHP_EOL;
+    echo "<Interceptor {$i} registered: " . ($res ? 'true' : 'false') . ">" . PHP_EOL;
 }
 
 $test = new TestClass();
@@ -45,6 +45,7 @@ $paramsArray = [null, 'test', 'error', 'another test'];
 foreach ($paramsArray as $i => $param) {
     $paramString = isset($param) ? $param : '';
     echo "<Execution #{$i} with param: {$paramString}>" . PHP_EOL;
+
     try {
         $result = $test->method($param);
         echo "<Result: " . ($result ? 'true' : 'false') . ">" . PHP_EOL;
@@ -54,7 +55,6 @@ foreach ($paramsArray as $i => $param) {
 }
 
 echo "<END TEST>" . PHP_EOL;
-?>
 --EXPECT--
 <TEST>
 <Interceptor 0 registered: true>