Fix "cargo doc" broken links

`cargo doc` was failing because it could not find the non-existing
`parse_private_key_der_any_bits`. This CL fixes it so `cargo doc`
is happy.

Change-Id: I6fef4ad0e7d4cbda237475bd4828cf2ccfa6e420
diff --git a/src/public/rsa/mod.rs b/src/public/rsa/mod.rs
index 548615a..7cdd395 100644
--- a/src/public/rsa/mod.rs
+++ b/src/public/rsa/mod.rs
@@ -226,7 +226,7 @@
 /// An RSA public key whose bit length is unknown at compile time.
 ///
 /// An `RsaPubKeyAnyBits` is an enum of [`RsaPubKey`]s over all supported bit
-/// lengths. It is returned from [`parse_public_key_der_any_bits`].
+/// lengths. It is returned from [`RsaPubKeyAnyBits::parse_from_der`].
 #[allow(missing_docs)]
 #[derive(Debug)]
 pub enum RsaPubKeyAnyBits {
@@ -286,7 +286,7 @@
 /// An RSA private key whose bit length is unknown at compile time.
 ///
 /// An `RsaPrivKeyAnyBits` is an enum of [`RsaPrivKey`]s over all supported bit
-/// lengths. It is returned from [`parse_private_key_der_any_bits`].
+/// lengths. It is returned from [`RsaPrivKeyAnyBits::parse_from_der`].
 #[allow(missing_docs)]
 #[derive(Debug)]
 pub enum RsaPrivKeyAnyBits {