Fix warnings in cranelift-codegen docs builds (#5292)

cranelift/codegen/src/ir/extfunc.rs

@@ -321,8 +321,8 @@ pub struct ExtFuncData {
     /// flag is best used when the target is known to be in the same unit of code generation, such
     /// as a Wasm module.
     ///
-    /// See the documentation for [`RelocDistance`](crate::machinst::RelocDistance) for more details. A
-    /// `colocated` flag value of `true` implies `RelocDistance::Near`.
+    /// See the documentation for `RelocDistance` for more details. A `colocated` flag value of
+    /// `true` implies `RelocDistance::Near`.
     pub colocated: bool,
 }