Correct ordering of PatchLineComments in ChangeNotes

The ordering of the comment comparator in ChangeNotes should match the
ordering defined in the PatchLineCommentAccess (compare filename, then
line number, then writtenOn).

Change-Id: Icc96f807f6e8a954f9e0a922e777278cb86a3bf1
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeNotes.java b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeNotes.java
index a92e80a..b242d7c 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeNotes.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeNotes.java
@@ -103,8 +103,8 @@
       String filename1 = c1.getKey().getParentKey().get();
       String filename2 = c2.getKey().getParentKey().get();
       return ComparisonChain.start()
-          .compare(c1.getLine(), c2.getLine())
           .compare(filename1, filename2)
+          .compare(c1.getLine(), c2.getLine())
           .compare(c1.getWrittenOn(), c2.getWrittenOn())
           .result();
     }