Fix test for PR #49268

Author: ordovicia

src/test/ui/issue-49257.rs

@@ -18,6 +18,5 @@ struct Point { x: u8, y: u8 }
 fn main() {
     let p = Point { x: 0, y: 0 };
     let Point { .., y } = p; //~ ERROR expected `}`, found `,`
-    //~| ERROR pattern does not mention field `x`
-    //~| ERROR pattern does not mention field `y`
+    //~| ERROR pattern does not mention fields `x`, `y`
 }

src/test/ui/issue-49257.stderr

@@ -4,18 +4,12 @@ error: expected `}`, found `,`
 LL |     let Point { .., y } = p; //~ ERROR expected `}`, found `,`
    |                   ^ `..` must be in the last position, and cannot have a trailing comma
 
-error[E0027]: pattern does not mention field `x`
+error[E0027]: pattern does not mention fields `x`, `y`
   --> $DIR/issue-49257.rs:20:9
    |
 LL |     let Point { .., y } = p; //~ ERROR expected `}`, found `,`
-   |         ^^^^^^^^^^^^^^^ missing field `x`
+   |         ^^^^^^^^^^^^^^^ missing fields `x`, `y`
 
-error[E0027]: pattern does not mention field `y`
-  --> $DIR/issue-49257.rs:20:9
-   |
-LL |     let Point { .., y } = p; //~ ERROR expected `}`, found `,`
-   |         ^^^^^^^^^^^^^^^ missing field `y`
-
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0027`.