Fix typo in doc comment.

call_one_force -> call_once_force

Author: emosenkis

src/libstd/sync/once.rs

@@ -272,7 +272,7 @@ impl Once {
     /// result in an immediate panic. If `f` panics, the `Once` will remain
     /// in a poison state. If `f` does _not_ panic, the `Once` will no
     /// longer be in a poison state and all future calls to `call_once` or
-    /// `call_one_force` will be no-ops.
+    /// `call_once_force` will be no-ops.
     ///
     /// The closure `f` is yielded a [`OnceState`] structure which can be used
     /// to query the poison status of the `Once`.