Fix a variable name

Author: Bozhidar Batsov

cider-macroexpansion.el

@@ -73,7 +73,7 @@ This variable specifies both what was expanded and the expander.")
 (defun cider-macroexpand-again ()
   "Repeat the last macroexpansion."
   (interactive)
-  (cider-initialize-macroexpansion-buffer cider-last-macroexpansion-expression nrepl-buffer-ns))
+  (cider-initialize-macroexpansion-buffer cider-last-macroexpand-expression nrepl-buffer-ns))
 
 ;;;###autoload
 (defun cider-macroexpand-1 (&optional prefix)