Simplify BanCommitResult type

The default constructor is not required, as Java will supply one.

Use ArrayList(4) instead of LinkedList. Its about the same size
for 1 commit, and smaller for higher numbers. Callers do not
perform insertions or removals from the middle of the lists.

Change-Id: Ib0e0c857697a6347dcb90c4c14f84555c2fd7c2a
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/BanCommitResult.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/BanCommitResult.java
index baae629..c1afb6b 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/BanCommitResult.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/BanCommitResult.java
@@ -16,17 +16,13 @@
 
 import org.eclipse.jgit.lib.ObjectId;
 
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 
 public class BanCommitResult {
-
-  private final List<ObjectId> newlyBannedCommits = new LinkedList<>();
-  private final List<ObjectId> alreadyBannedCommits = new LinkedList<>();
-  private final List<ObjectId> ignoredObjectIds = new LinkedList<>();
-
-  public BanCommitResult() {
-  }
+  private final List<ObjectId> newlyBannedCommits = new ArrayList<>(4);
+  private final List<ObjectId> alreadyBannedCommits = new ArrayList<>(4);
+  private final List<ObjectId> ignoredObjectIds = new ArrayList<>(4);
 
   public void commitBanned(final ObjectId commitId) {
     newlyBannedCommits.add(commitId);