CheckOperationsImpl#notesAsText: Don't create 2 ObjectReaders

RevWalk already has an ObjectReader, just use that one instead of
creating a new one.

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I1c5d2b499b7a18a1e0834853b9d64489a8d1dca5
diff --git a/java/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImpl.java b/java/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImpl.java
index a6a1c02..9d28a48 100644
--- a/java/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImpl.java
+++ b/java/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImpl.java
@@ -33,7 +33,6 @@
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
-import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.notes.Note;
@@ -96,9 +95,7 @@
             repo.getRefDatabase().exactRef(CheckerRef.checksRef(key.patchSet().changeId));
         checkNotNull(checkRef);
 
-        ObjectReader reader = repo.newObjectReader();
-
-        NoteMap notes = NoteMap.read(reader, rw.parseCommit(checkRef.getObjectId()));
+        NoteMap notes = NoteMap.read(rw.getObjectReader(), rw.parseCommit(checkRef.getObjectId()));
         ImmutableMap.Builder<RevId, String> raw = ImmutableMap.builder();
 
         for (Note note : notes) {