Run rustfmt.

embassy-stm32/src/usart/buffered.rs

@@ -1,6 +1,7 @@
-use atomic_polyfill::{compiler_fence, Ordering};
 use core::future::Future;
 use core::task::Poll;
+
+use atomic_polyfill::{compiler_fence, Ordering};
 use embassy::waitqueue::WakerRegistration;
 use embassy_cortex_m::peripheral::{PeripheralMutex, PeripheralState, StateStorage};
 use embassy_hal_common::ring_buffer::RingBuffer;