multi: fix various typos

htlcswitch/interfaces.go

@@ -139,7 +139,7 @@ type ChannelUpdateHandler interface {
 	// the state already allowed those adds.
 	EnableAdds(direction LinkDirection) error
 
-	// DiableAdds sets the ChannelUpdateHandler state to allow
+	// DisableAdds sets the ChannelUpdateHandler state to allow
 	// UpdateAddHtlc's in the specified direction. It returns an error if
 	// the state already disallowed those adds.
 	DisableAdds(direction LinkDirection) error

htlcswitch/link.go

@@ -636,7 +636,7 @@ func (l *channelLink) EnableAdds(linkDirection LinkDirection) error {
 	return nil
 }
 
-// DiableAdds sets the ChannelUpdateHandler state to allow UpdateAddHtlc's in
+// DisableAdds sets the ChannelUpdateHandler state to allow UpdateAddHtlc's in
 // the specified direction. It returns an error if the state already disallowed
 // those adds.
 func (l *channelLink) DisableAdds(linkDirection LinkDirection) error {