Merge pull request #4638 from kasimtan/phpdoc_fixes

[ci skip] Fixed PHPDoc parameter name and type discrepancies
diff --git a/system/libraries/Session/Session.php b/system/libraries/Session/Session.php
index 1bdc6e5..3b391a8 100644
--- a/system/libraries/Session/Session.php
+++ b/system/libraries/Session/Session.php
@@ -730,7 +730,7 @@
 	 *
 	 * Legacy CI_Session compatibility method
 	 *
-	 * @param	mixed	$data	Session data key(s)
+	 * @param	mixed	$key	Session data key(s)
 	 * @return	void
 	 */
 	public function unset_userdata($key)