Fix depreciation warning typos

Author: Tibo-lg

src/ecdsa/mod.rs

@@ -442,7 +442,7 @@ impl<C: Signing> Secp256k1<C> {
     /// signature implementation of bitcoin core. In average, this function
     /// will perform two signing operations.
     /// Requires a signing capable context.
-    #[deprecated(since = "0.21.0", note = "Use sign_ecdsa_grind_r instead.")]
+    #[deprecated(since = "0.21.0", note = "Use sign_ecdsa_low_r instead.")]
     pub fn sign_low_r(&self, msg: &Message, sk: &SecretKey) -> Signature {
         self.sign_grind_with_check(msg, sk, compact_sig_has_zero_first_bit)
     }

src/schnorr.rs

@@ -262,7 +262,7 @@ impl <C: Signing> Secp256k1<C> {
     #[inline]
     #[cfg(any(test, feature = "rand"))]
     #[cfg_attr(docsrs, doc(cfg(feature = "rand")))]
-    #[deprecated(since = "0.21.0", note = "Use kp = KeyPair::new() and kp.public_key()")]
+    #[deprecated(since = "0.21.0", note = "Use kp = KeyPair::new() and kp.x_only_public_key().0")]
     pub fn generate_schnorrsig_keypair<R: Rng + ?Sized>(
         &self,
         rng: &mut R,