Bump clippy & Fix warnings (#2109)

* Bump clippy

* Fixing warnings

parity/boot.rs

@@ -54,12 +54,10 @@ pub fn payload<B: ipc::BinaryConvertable>() -> Result<B, BootError> {
 
 	let mut buffer = Vec::new();
 	try!(
-		io::stdin().read_to_end(&mut buffer)
-			.map_err(|io_err| BootError::ReadArgs(io_err))
+		io::stdin().read_to_end(&mut buffer).map_err(BootError::ReadArgs)
 	);
 
-	ipc::binary::deserialize::<B>(&buffer)
-		.map_err(|binary_error| BootError::DecodeArgs(binary_error))
+	ipc::binary::deserialize::<B>(&buffer).map_err(BootError::DecodeArgs)
 }
 
 pub fn register(hv_url: &str, control_url: &str, module_id: IpcModuleId) -> GuardedSocket<HypervisorServiceClient<NanoSocket>>{
@@ -73,7 +71,7 @@ pub fn register(hv_url: &str, control_url: &str, module_id: IpcModuleId) -> Guar
 pub fn dependency<C: WithSocket<NanoSocket>>(url: &str)
 	-> Result<GuardedSocket<C>, BootError>
 {
-	nanoipc::generic_client::<C>(url).map_err(|socket_err| BootError::DependencyConnect(socket_err))
+	nanoipc::generic_client::<C>(url).map_err(BootError::DependencyConnect)
 }
 
 pub fn main_thread() -> Arc<AtomicBool> {

parity/cli/usage.rs

@@ -169,14 +169,10 @@ macro_rules! usage {
 						let result = rustc_serialize::Decodable::decode(&mut toml::Decoder::new(toml::Value::Table(value)));
 						match result {
 							Ok(config) => Ok(config),
-							Err(e) => {
-								return Err(e.into());
-							}
+							Err(e) => Err(e.into()),
 						}
 					},
-					None => {
-						return Err(ArgsError::Parsing(value_parser.errors));
-					},
+					None => Err(ArgsError::Parsing(value_parser.errors)),
 				}
 			}