Duplicate error messages have been fixed

test_suite/tests/compile-fail/remote/missing_field.rs

@@ -16,7 +16,7 @@ mod remote {
     }
 }
 
-#[derive(Serialize, Deserialize)] //~ ERROR: missing field `b` in initializer of `remote::S`
+#[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::S")]
 struct S {
     a: u8, //~^^^ ERROR: missing field `b` in initializer of `remote::S`

test_suite/tests/compile-fail/remote/unknown_field.rs

@@ -19,8 +19,7 @@ mod remote {
 #[serde(remote = "remote::S")]
 struct S {
     //~^^^ ERROR: struct `remote::S` has no field named `b`
-    //~^^^^ ERROR: struct `remote::S` has no field named `b`
+    b: u8, //~^^^^ ERROR: no field `b` on type `&remote::S`
-    b: u8, //~^^^^^ ERROR: no field `b` on type `&remote::S`
 }
 
 fn main() {}