set Err to true for test

This was likely meant to be set to Err true but
the old parser mistakenly didn't raise an error

helper/schema/schema_test.go

@@ -5296,7 +5296,6 @@ func TestSchemaMap_Validate(t *testing.T) {
 			},
 			Err: false,
 		},
-		/* FIXME err: "block.0.int": required field is not set
 		"unexpected nils values": {
 			Schema: map[string]*Schema{
 				"strings": &Schema{
@@ -5328,8 +5327,8 @@ func TestSchemaMap_Validate(t *testing.T) {
 					nil,
 				},
 			},
+			Err: true,
 		},
-		*/
 	}
 
 	for tn, tc := range cases {