Enter/Return after completed form doesn't unindent

[WalterGR]

Repro:

1. Open or create a .clj file.
2. Type the following, leaving the cursor where shown.

(defn index-of-any [pred coll]
  (first (index-filter pred coll)))_

3. Press Enter/Return.

Expected:

Cursor is at the first column in the new line.

(defn index-of-any [pred coll]
  (first (index-filter pred coll)))
_

Actual:

Cursor is still indented, even though the form has been completed (i.e. parens and brackets match.)

(defn index-of-any [pred coll]
  (first (index-filter pred coll)))
  _