babel: css: Delete unnecessary language-specific expansion function

	* ob-css.el (org-babel-expand-body:css): Delete
	function (automatically handled by generic version)

lisp/ob-css.el

@@ -32,9 +32,6 @@
 
 (defvar org-babel-default-header-args:css '())
 
-(defun org-babel-expand-body:css (body params)
-  "Expand BODY according to PARAMS, return the expanded body." body)
-
 (defun org-babel-execute:css (body params)
   "Execute a block of CSS code.
 This function is called by `org-babel-execute-src-block'."