firestore: remove erroneous TODO comment
I have no idea why I wrote this TODO, but everything seems to work,
tests pass, and this just confuses people reading the snippet in the
docs.
@@ -176,7 +176,7 @@ func updateDocNested(ctx context.Context, client *firestore.Client) error {
"favorites": map[string]interface{}{
"color": "Red",
},
- }, firestore.MergeAll) // TODO(cbro): this should fail
+ }, firestore.MergeAll)
if err != nil {
return err
}
