Generic/InterfaceNameSuffix: rename test case file

Doing this to be able to create tests with syntax errors in additional,
separate test case files.

Author: rodrigoprimo

src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.inc renamed to src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.1.inc

@@ -25,11 +25,18 @@ final class InterfaceNameSuffixUnitTest extends AbstractSniffUnitTest
      * The key of the array should represent the line number and the value
      * should represent the number of errors that should occur on that line.
      *
+     * @param string $testFile The name of the test file.
+     *
      * @return array<int, int>
      */
-    public function getErrorList()
+    public function getErrorList($testFile='')
     {
-        return [5 => 1];
+        switch ($testFile) {
+        case 'InterfaceNameSuffixUnitTest.1.inc':
+            return [5 => 1];
+        default:
+            return [];
+        }
 
     }//end getErrorList()