fix a few clippy lints on files that are touched

src/hardware/adc.rs

@@ -81,6 +81,7 @@ use hal::dma::{
 #[derive(Copy, Clone)]
 pub struct AdcCode(pub u16);
 
+#[allow(clippy::from_over_into)]
 impl Into<f32> for AdcCode {
     /// Convert raw ADC codes to/from voltage levels.
     ///

src/hardware/dac.rs

@@ -73,6 +73,7 @@ static mut DAC_BUF: [[SampleBuffer; 2]; 2] = [[[0; SAMPLE_BUFFER_SIZE]; 2]; 2];
 #[derive(Copy, Clone)]
 pub struct DacCode(pub u16);
 
+#[allow(clippy::from_over_into)]
 impl Into<f32> for DacCode {
     fn into(self) -> f32 {
         // The DAC output range in bipolar mode (including the external output op-amp) is +/- 4.096
@@ -104,7 +105,7 @@ macro_rules! dac_output {
                 _channel: timers::tim2::$trigger_channel,
                 spi: hal::spi::Spi<hal::stm32::$spi, hal::spi::Disabled, u16>,
             ) -> Self {
-                Self { _channel, spi }
+                Self { spi, _channel }
             }
 
             /// Start the SPI and begin operating in a DMA-driven transfer mode.

src/net/miniconf_client.rs

@@ -103,7 +103,7 @@ where
             let path = match topic.strip_prefix(prefix) {
                 // For paths, we do not want to include the leading slash.
                 Some(path) => {
-                    if path.len() > 0 {
+                    if !path.is_empty() {
                         &path[1..]
                     } else {
                         path
@@ -117,9 +117,9 @@ where
 
             let message: SettingsResponse = settings
                 .string_set(path.split('/').peekable(), message)
-                .and_then(|_| {
+                .map(|_| {
                     update = true;
-                    Ok(())
+                    ()
                 })
                 .into();