fix typo

frame/support/procedural/src/pallet/expand/storage.rs

@@ -50,15 +50,15 @@ fn counter_prefix(prefix: &str) -> String {
 fn check_prefix_duplicates(
 	storage_def: &StorageDef,
 	// A hashmap of all already used prefix and their associated error if duplication
-	used_prefix: &mut HashMap<String, syn::Error>,
+	used_prefixes: &mut HashMap<String, syn::Error>,
 ) -> syn::Result<()> {
 	let prefix = storage_def.prefix();
 	let dup_err = syn::Error::new(
 		storage_def.prefix_span(),
 		format!("Duplicate storage prefixes found for `{}`", prefix),
 	);
 
-	if let Some(other_dup_err) = used_prefix.insert(prefix.clone(), dup_err.clone()) {
+	if let Some(other_dup_err) = used_prefixes.insert(prefix.clone(), dup_err.clone()) {
 		let mut err = dup_err;
 		err.combine(other_dup_err);
 		return Err(err)
@@ -76,7 +76,7 @@ fn check_prefix_duplicates(
 		);
 
 		if let Some(other_dup_err) =
-			used_prefix.insert(counter_prefix.clone(), counter_dup_err.clone())
+			used_prefixes.insert(counter_prefix.clone(), counter_dup_err.clone())
 		{
 			let mut err = counter_dup_err;
 			err.combine(other_dup_err);