Apply PR feedback

Author: lithp

eth/validation.py

@@ -53,9 +53,7 @@ def validate_is_bytes(value: bytes, title: str="Value") -> None:
 
 def validate_is_bytes_or_view(value: Union[bytes, memoryview],
                               title: str="Value") -> None:
-    if isinstance(value, bytes):
-        return
-    if isinstance(value, memoryview):
+    if isinstance(value, (bytes, memoryview)):
         return
     raise ValidationError(
         "{title} must be bytes or memoryview. Got {0}".format(type(value), title=title)