minor wording improvement [skip ci]

typer.ml

@@ -831,7 +831,7 @@ let unify_field_call ctx fa el args ret p inline =
 					display_error ctx ("Overload resolution failed for " ^ (s_type (print_context()) cf.cf_type)) p;
 					display_error ctx msg p2;
 				) failures;
-				error "End of overload fail reasons" p
+				error "End of overload failure reasons" p
 			end
 		in
 		if is_overload && ctx.com.config.pf_overload then begin match Codegen.Overloads.reduce_compatible candidates with