wip: simplify formatMessage internal logic

src/sha3.js

@@ -64,12 +64,10 @@
     if (type === 'string') {
       return [message, false];
     }
-    if (type !== 'object') {
+    if (type !== 'object' || message === null) {
       throw new Error(INPUT_ERROR);
     }
-    if (message === null) {
-      throw new Error(INPUT_ERROR);
-    } else if (ARRAY_BUFFER && message.constructor === ArrayBuffer) {
+    if (ARRAY_BUFFER && message.constructor === ArrayBuffer) {
       message = new Uint8Array(message);
     } else if (!isArray(message) && !isView(message)) {
       throw new Error(INPUT_ERROR);