Fix warnings and make CI working again (#4469)

* Fix warnings and make CI working again

* Fix test

substrate/client/authority-discovery/src/lib.rs

@@ -693,7 +693,7 @@ mod tests {
 			&self,
 			_: &BlockId<Block>,
 			_: ExecutionContext,
-			_: Option<(Block)>,
+			_: Option<Block>,
 			_: Vec<u8>,
 		) -> std::result::Result<NativeOrEncoded<()>, sp_blockchain::Error> {
 			unimplemented!("Not required for testing!")

substrate/client/finality-grandpa/src/tests.rs

@@ -225,7 +225,7 @@ impl Core<Block> for RuntimeApi {
 		&self,
 		_: &BlockId<Block>,
 		_: ExecutionContext,
-		_: Option<(Block)>,
+		_: Option<Block>,
 		_: Vec<u8>,
 	) -> Result<NativeOrEncoded<()>> {
 		unimplemented!("Not required for testing!")

substrate/client/src/light/backend.rs

@@ -62,7 +62,7 @@ pub struct ImportOperation<Block: BlockT, S, H: Hasher> {
 	finalized_blocks: Vec<BlockId<Block>>,
 	set_head: Option<BlockId<Block>>,
 	storage_update: Option<InMemoryState<H>>,
-	_phantom: ::std::marker::PhantomData<(S)>,
+	_phantom: ::std::marker::PhantomData<S>,
 }
 
 /// Either in-memory genesis state, or locally-unavailable state.