Less slices (#9176)

* Less slices

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/primitives/runtime/src/generic/mod.rs

@@ -44,7 +44,7 @@ fn encode_with_vec_prefix<T: Encode, F: Fn(&mut Vec<u8>)>(encoder: F) -> Vec<u8>
 	let size = ::sp_std::mem::size_of::<T>();
 	let reserve = match size {
 		0..=0b00111111 => 1,
-		0..=0b00111111_11111111 => 2,
+		0b01000000..=0b00111111_11111111 => 2,
 		_ => 4,
 	};
 	let mut v = Vec::with_capacity(reserve + size);