8194649: Minor cleanup of parameter checking in ByteArrayOutputStream and ObjectInputStream

Reviewed-by: rriggs

src/java.base/share/classes/java/io/ObjectInputStream.java

@@ -1296,7 +1296,6 @@ public class ObjectInputStream
      * @throws InvalidClassException if the filter rejects creation
      */
     private void checkArray(Class<?> arrayType, int arrayLength) throws InvalidClassException {
-        Objects.requireNonNull(arrayType);
         if (! arrayType.isArray()) {
             throw new IllegalArgumentException("not an array type");
         }