Remove unused getTreeId from TreeFormatter

Change-Id: If5955757575d4c6053b6f8109e9dc2ecb0502446
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Reviewed-by: Chris Aniszczyk <caniszczyk@gmail.com>

org.eclipse.jgit/src/org/eclipse/jgit/lib/TreeFormatter.java

@@ -270,25 +270,6 @@ public class TreeFormatter {
 		overflowBuffer.write((byte) 0);
 	}
 
-	/**
-	 * Compute the current tree's ObjectId.
-	 *
-	 * @return computed ObjectId of the tree
-	 */
-	public ObjectId getTreeId() {
-		final ObjectInserter.Formatter fmt = new ObjectInserter.Formatter();
-		if (buf != null)
-			return fmt.idFor(OBJ_TREE, buf, 0, ptr);
-
-		try {
-			final long len = overflowBuffer.length();
-			return fmt.idFor(OBJ_TREE, len, overflowBuffer.openInputStream());
-		} catch (IOException err) {
-			// This should never happen, its read failure on a byte array.
-			throw new RuntimeException(err);
-		}
-	}
-
 	/**
 	 * Insert this tree and obtain its ObjectId.
 	 *