style(all): Address suggestions made by rust-clippy

src/header/shared/entity.rs

@@ -109,9 +109,10 @@ impl EntityTag {
 
 impl Display for EntityTag {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self.weak {
-            true => write!(f, "W/\"{}\"", self.tag),
-            false => write!(f, "\"{}\"", self.tag),
+        if self.weak {
+            write!(f, "W/\"{}\"", self.tag)
+        } else {
+            write!(f, "\"{}\"", self.tag)
         }
     }
 }

src/header/shared/quality_item.rs

@@ -101,7 +101,7 @@ impl<T: str::FromStr> str::FromStr for QualityItem<T> {
         match raw_item.parse::<T>() {
             // we already checked above that the quality is within range
             Ok(item) => Ok(QualityItem::new(item, from_f32(quality))),
-            Err(_) => return Err(::Error::Header),
+            Err(_) => Err(::Error::Header),
         }
     }
 }