multi: fix spelling mistakes

watchtower/wtdb/client_session.go

@@ -116,6 +116,6 @@ type CommittedUpdate struct {
 
 	// EncryptedBlob is a ciphertext containing the sweep information for
 	// exacting justice if the commitment transaction matching the breach
-	// hint is braodcast.
+	// hint is broadcast.
 	EncryptedBlob []byte
 }

watchtower/wtdb/session_state_update.go

@@ -20,7 +20,7 @@ type SessionStateUpdate struct {
 
 	// EncryptedBlob is a ciphertext containing the sweep information for
 	// exacting justice if the commitment transaction matching the breach
-	// hint is braodcast.
+	// hint is broadcast.
 	EncryptedBlob []byte
 }