Revert "frame/remote-externalities: Eliminate side effect on batch re…

…quest failure"

This reverts commit 3678529.

utils/frame/remote-externalities/src/lib.rs

@@ -516,8 +516,6 @@ where
 		// `pending_ext`.
 		let mut terminated = 0usize;
 		let mut batch_failed = false;
-		let mut batch_kv = Vec::with_capacity(keys.len());
-
 		loop {
 			match rx.next().await.unwrap() {
 				Message::Batch(kv) => {
@@ -526,7 +524,7 @@ where
 						if is_default_child_storage_key(k.as_ref()) {
 							continue
 						}
-						batch_kv.push((k, v));
+						pending_ext.insert(k, v);
 					}
 				},
 				Message::BatchFailed(error) => {
@@ -551,11 +549,6 @@ where
 			return Err("Batch failed.")
 		}
 
-		// Ensure that `pending_ext` is populated only if the batch succeeded.
-		for (k, v) in batch_kv.into_iter() {
-			pending_ext.insert(k, v);
-		}
-
 		Ok(keys_and_values)
 	}