Remove unnecessary mut and document possible panic

src/cache.rs

@@ -74,7 +74,7 @@ impl<'a> CacheState<'a> {
         trace!("Calculating new cache");
         match self {
             CacheState::Old { mut cache, .. } => {
-                if let Some(mut cache) = cache.entries.get_mut(branch) {
+                if let Some(cache) = cache.entries.get_mut(branch) {
                     cache.head = head;
                     cache.count += count;
                     cache.commits += commits;

src/telemetry.rs

@@ -15,6 +15,10 @@ pub fn get_subscriber(name: &str, env_filter: &str) -> impl Subscriber + Send +
         .with(formatting_layer)
 }
 
+/// # Panics
+///
+/// This panics if the `LogTracer` cannot be initialized or `subscriber` cannot be set as global
+/// default.
 pub fn init_subscriber(subscriber: impl Subscriber + Send + Sync) {
     LogTracer::init().expect("Failed to set logger");
     set_global_default(subscriber).expect("Failed to set tracing subscriber");