cmd/swarm: update should error on manifest mismatch (#18047)

* cmd/swarm: fix ethersphere/go-ethereum#979:

update should error on manifest mistmatch

* cmd/swarm: fixed comments and remove sprintf from log.Info

* cmd/swarm: remove unnecessary comment

cmd/swarm/feeds.go

@@ -169,7 +169,6 @@ func feedUpdate(ctx *cli.Context) {
 		query = new(feed.Query)
 		query.User = signer.Address()
 		query.Topic = getTopic(ctx)
-
 	}
 
 	// Retrieve a feed update request
@@ -178,6 +177,11 @@ func feedUpdate(ctx *cli.Context) {
 		utils.Fatalf("Error retrieving feed status: %s", err.Error())
 	}
 
+	// Check that the provided signer matches the request to sign
+	if updateRequest.User != signer.Address() {
+		utils.Fatalf("Signer address does not match the update request")
+	}
+
 	// set the new data
 	updateRequest.SetData(data)