guardmgr: fix rustdoc references.

crates/tor-guardmgr/src/guard.rs

@@ -72,8 +72,8 @@ impl CrateId {
 ///
 /// A Guard is a Tor relay that clients use for the first hop of their circuits.
 /// It doesn't need to be a relay that's currently on the network (that is, one
-/// that we could represent as a [`Relay`]): guards might be temporarily
-/// unlisted.
+/// that we could represent as a [`Relay`](tor_netdir::Relay)): guards might be
+/// temporarily unlisted.
 ///
 /// Some fields in guards are persistent; others are reset with every process.
 ///

crates/tor-guardmgr/src/sample.rs

@@ -482,7 +482,7 @@ impl GuardSet {
     }
 
     /// Return the number of our primary guards are missing directory
-    /// information in [`universe`].
+    /// information in `universe`.
     pub(crate) fn n_primary_without_dir_info<U: Universe>(&mut self, universe: &U) -> usize {
         self.primary
             .iter()