Remove unneeded imports

Author: teskje

src/serial.rs

@@ -8,8 +8,6 @@ use crate::{
     time::Bps,
 };
 use core::{convert::Infallible, marker::PhantomData, ptr};
-use cortex_m::interrupt;
-use nb;
 
 #[cfg(any(
     feature = "stm32f302",
@@ -41,6 +39,8 @@ use crate::gpio::gpioe;
 
 #[cfg(feature = "stm32f303")]
 use crate::dma;
+#[cfg(feature = "stm32f303")]
+use cortex_m::interrupt;
 
 /// Interrupt event
 pub enum Event {

src/spi.rs

@@ -5,7 +5,6 @@ use core::ptr;
 use crate::hal::spi::FullDuplex;
 pub use crate::hal::spi::{Mode, Phase, Polarity};
 use crate::pac::{SPI1, SPI2, SPI3};
-use nb;
 
 use crate::gpio::gpioa::{PA5, PA6, PA7};
 #[cfg(any(

src/timer.rs

@@ -56,7 +56,6 @@ use crate::pac::{TIM15, TIM16, TIM17, TIM2, TIM6};
 use crate::pac::{TIM3, TIM7};
 
 use cast::{u16, u32};
-use nb;
 use void::Void;
 
 use crate::rcc::{Clocks, APB1, APB2};