Fix comment typo in Form_validation.php
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 9491f35..3e0c72e 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -101,7 +101,7 @@
 			return $this;
 		}
 
-		// If an array was passed via the first parameter instead of indidual string
+		// If an array was passed via the first parameter instead of individual string
 		// values we cycle through it and recursively call this function.
 		if (is_array($field))
 		{