Fix comparison using reference equality instead of value equality

Change-Id: I635573a20bdaabf07f4aac2f9eda4f943764ee02
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/MergeUtil.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/MergeUtil.java
index 9124c62..2025e99 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/MergeUtil.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/MergeUtil.java
@@ -79,6 +79,7 @@
 import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Objects;
 import java.util.Set;
 
 public class MergeUtil {
@@ -658,7 +659,7 @@
       rw.markStart(mergeTip);
       for (RevCommit c : alreadyAccepted) {
         // If branch was not created by this submit.
-        if (c != mergeTip) {
+        if (!Objects.equals(c, mergeTip)) {
           rw.markUninteresting(c);
         }
       }