result -> finalize in readme (#180)

Author: rukai

README.md

@@ -94,7 +94,7 @@ let data = b"Hello world!";
 hasher.update(data);
 // `update` can be called repeatedly and is generic over `AsRef<[u8]>`
 hasher.update("String data");
-// Note that calling `result()` consumes hasher
+// Note that calling `finalize()` consumes hasher
 let hash = hasher.finalize();
 println!("Result: {:x}", hash);
 ```