Fix IbcDestinationCallbackMsg docs

Author: chipshort

packages/std/src/ibc/callbacks.rs

@@ -179,11 +179,8 @@ impl IbcTimeoutCallbackMsg {
 /// It is important to validate that the packet and acknowledgement are what you expect them to be.
 /// For example for a transfer message, the receiver is not necessarily the contract itself.
 ///
-/// The callback is called after the packet was acknowledged on the destination chain, as follows:
-/// - If the acknowledgement is synchronous (i.e. returned immediately when the packet is received),
-///   the callback is called only if the acknowledgement was successful.
-/// - If the acknowledgement is asynchronous (i.e. written later using `WriteAcknowledgement`),
-///   the callback is called regardless of the success of the acknowledgement.
+/// The callback is called when the packet is being acknowledged on the destination chain.
+/// This happens for both synchronous and asynchronous acknowledgements.
 ///
 /// Note that there are some prerequisites that need to be fulfilled to receive destination callbacks:
 /// - The contract must implement the `ibc_destination_callback` entrypoint.