fix: variable referenced before assignment (#21560)

diff --git a/erpnext/controllers/buying_controller.py b/erpnext/controllers/buying_controller.py
index 0e72ec2..608e537 100644
--- a/erpnext/controllers/buying_controller.py
+++ b/erpnext/controllers/buying_controller.py
@@ -101,7 +101,7 @@
 				for d in tax_for_valuation:
 					d.category = 'Total'
 				msgprint(_('Tax Category has been changed to "Total" because all the Items are non-stock items'))
-	
+
 	def validate_asset_return(self):
 		if self.doctype not in ['Purchase Receipt', 'Purchase Invoice'] or not self.is_return:
 			return
@@ -691,10 +691,10 @@
 						for qty in range(cint(d.qty)):
 							asset = self.make_asset(d)
 							created_assets.append(asset)
-						
+
 						if len(created_assets) > 5:
 							# dont show asset form links if more than 5 assets are created
-							messages.append(_('{} Asset{} created for {}').format(len(created_assets), is_plural, frappe.bold(d.item_code)))
+							messages.append(_('{} Assets created for {}').format(len(created_assets), frappe.bold(d.item_code)))
 						else:
 							assets_link = list(map(lambda d: frappe.utils.get_link_to_form('Asset', d), created_assets))
 							assets_link = frappe.bold(','.join(assets_link))