resolve code review comments

Author: bitfield

clippy_lints/src/await_holding_invalid.rs

@@ -23,7 +23,7 @@ declare_clippy_lint! {
     /// type. Many asynchronous foundation crates provide such a `Mutex` type.
     /// The other solution is to ensure the mutex is unlocked before calling
     /// `await`, either by introducing a scope or an explicit call to
-    /// [`Drop::drop`].
+    /// [`Drop::drop`](https://doc.rust-lang.org/std/ops/trait.Drop.html).
     ///
     /// ### Known problems
     /// Will report false positive for explicitly dropped guards

clippy_lints/src/casts/mod.rs

@@ -219,7 +219,7 @@ declare_clippy_lint! {
     /// Dereferencing the resulting pointer may be undefined behavior.
     ///
     /// ### Known problems
-    /// Using [`std::ptr::read_unaligned`] and [`std::ptr::write_unaligned`] or
+    /// Using [`std::ptr::read_unaligned`](https://doc.rust-lang.org/std/ptr/fn.read_unaligned.html) and [`std::ptr::write_unaligned`](https://doc.rust-lang.org/std/ptr/fn.write_unaligned.html) or
     /// similar on the resulting pointer is fine. Is over-zealous: casts with
     /// manual alignment checks or casts like `u64` -> `u8` -> `u16` can be
     /// fine. Miri is able to do a more in-depth analysis.