Fix rustc and rustdoc errors on nightly

Author: jkczyz

lightning/src/ln/msgs.rs

@@ -985,7 +985,7 @@ impl fmt::Display for DecodeError {
 			DecodeError::InvalidValue => f.write_str("Nonsense bytes didn't map to the type they were interpreted as"),
 			DecodeError::ShortRead => f.write_str("Packet extended beyond the provided bytes"),
 			DecodeError::BadLengthDescriptor => f.write_str("A length descriptor in the packet didn't describe the later data correctly"),
-			DecodeError::Io(ref e) => e.fmt(f),
+			DecodeError::Io(ref e) => Debug::fmt(&e, f),
 			DecodeError::UnsupportedCompression => f.write_str("We don't support receiving messages with zlib-compressed fields"),
 		}
 	}

lightning/src/util/events.rs

@@ -236,7 +236,7 @@ pub enum Event {
 	/// Note that this does *not* indicate that all paths for an MPP payment have failed, see
 	/// [`Event::PaymentFailed`] and [`all_paths_failed`].
 	///
-	/// [`all_paths_failed`]: Self::all_paths_failed
+	/// [`all_paths_failed`]: Self::PaymentPathFailed::all_paths_failed
 	PaymentPathFailed {
 		/// The id returned by [`ChannelManager::send_payment`] and used with
 		/// [`ChannelManager::retry_payment`] and [`ChannelManager::abandon_payment`].