Fixing few clippy warnings

ethcore/src/blooms/group_position.rs

@@ -17,7 +17,7 @@
 use bloomchain::group as bc;
 use util::HeapSizeOf;
 
-/// Represents BloomGroup position in database.
+/// Represents `BloomGroup` position in database.
 #[derive(PartialEq, Eq, Hash, Clone, Debug)]
 pub struct GroupPosition {
 	/// Bloom level.

ethcore/src/trace/db.rs

@@ -54,7 +54,7 @@ impl Key<BlockTraces> for H256 {
 	}
 }
 
-/// Wrapper around blooms::GroupPosition so it could be
+/// Wrapper around `blooms::GroupPosition` so it could be
 /// uniquely identified in the database.
 #[derive(Debug, PartialEq, Eq, Hash, Clone)]
 struct TraceGroupPosition(blooms::GroupPosition);