Fixed a bug where $data was not being converted to an array properly in set_rules()

http://codeigniter.com/bug_tracker/bug/4220/
diff --git a/system/libraries/Validation.php b/system/libraries/Validation.php
index 16e8cd7..f628d86 100644
--- a/system/libraries/Validation.php
+++ b/system/libraries/Validation.php
@@ -117,7 +117,7 @@
 			if ($rules == '')

 				return;

 				

-			$data[$data] = $rules;

+			$data = array($data => $rules);

 		}

 	

 		foreach ($data as $key => $val)