Address review comments

homeassistant/config.py

@@ -585,6 +585,9 @@ def stringify_invalid(ex: vol.Invalid) -> str:
     is to format the path delimited by -> instead of @data[].
     """
     path = "->".join(str(m) for m in ex.path)
+    # This function is an alternative to the stringification done by
+    # vol.Invalid.__str__, so we need to call Exception.__str__ here
+    # instead of str(ex)
     output = Exception.__str__(ex)
     if error_type := ex.error_type:
         output += " for " + error_type
@@ -598,7 +601,7 @@ def humanize_error(
 ) -> str:
     """Provide a more helpful + complete validation error message.
 
-    This is a aodified version of voluptuous.error.Invalid.__str__,
+    This is a modified version of voluptuous.error.Invalid.__str__,
     the modifications make some minor changes to the formatting.
     """
     if isinstance(validation_error, vol.MultipleInvalid):
@@ -611,7 +614,7 @@ def humanize_error(
     offending_item_summary = repr(_get_by_path(data, validation_error.path))
     if len(offending_item_summary) > max_sub_error_length:
         offending_item_summary = (
-            offending_item_summary[: max_sub_error_length - 3] + "..."
+            f"{offending_item_summary[: max_sub_error_length - 3]}..."
         )
     return f"{stringify_invalid(validation_error)}, got {offending_item_summary}"