Update fourslashImpl.ts

Author: ulrichstark

src/harness/fourslashImpl.ts

@@ -2598,7 +2598,7 @@ export class TestState {
         const sorted = items.slice();
         // sort by file, then *backwards* by position in the file so I can insert multiple times on a line without counting
         sorted.sort((q1, q2) =>
-            q1.marker.fileName === q1.marker.fileName
+            q1.marker.fileName === q2.marker.fileName
                 ? (q1.marker.position > q2.marker.position ? -1 : 1)
                 : (q1.marker.fileName > q2.marker.fileName ? 1 : -1)
         );