render: require more rendering primitives to have Sync and/or Send

src/platform/smart_leds_lib.rs

@@ -73,7 +73,7 @@ impl<P: Pixbuf<Pixel=T::Color>, T: FastWrite> Output for StrideOutput<P, T> {
     }
 }
 
-pub trait FastWrite {
+pub trait FastWrite: Send {
     type Target: SmartLedsWrite;
     type Color: HardwarePixel;
     type Error;