std: fix broken internal doc links

Author: joboet

library/std/src/sys/common/thread_local/fast_local.rs

@@ -2,12 +2,13 @@
 //!
 //! To achieve the best performance, we need to differentiate between four types
 //! of TLS, resulting from the method of initialization used (`const` or lazy)
-//! and the drop requirements of the stored type, as indicated by [`needs_drop`].
-//! However, across these types a TLS variable can only be in three different
-//! different states, allowing us to use a common implementation specialized by
-//! type parameters. The three states are:
+//! and the drop requirements of the stored type, as indicated by
+//! [`needs_drop`](crate::mem::needs_drop). However, across these types a TLS
+//! variable can only be in three different different states, allowing us to
+//! use a common implementation specialized by type parameters. The three states
+//! are:
 //!
-//! 1. [`Initial`](State::Inital): the destructor has not been registered and/or
+//! 1. [`Initial`](State::Initial): the destructor has not been registered and/or
 //!    the variable is uninitialized.
 //! 2. [`Alive`](State::Alive): if it exists, the destructor is registered. The
 //!    variable is initialized.