Remove lingering mention of 'priv' in the reference

Author: carols10cents

src/doc/reference.md

@@ -1562,8 +1562,7 @@ warnings are generated, or otherwise "you used a private item of another module
 and weren't allowed to."
 
 By default, everything in Rust is *private*, with one exception. Enum variants
-in a `pub` enum are also public by default. You are allowed to alter this
-default visibility with the `priv` keyword. When an item is declared as `pub`,
+in a `pub` enum are also public by default. When an item is declared as `pub`,
 it can be thought of as being accessible to the outside world. For example:
 
 ```