Update test for question_mark to cover Result

tests/ui/question_mark.fixed

@@ -104,6 +104,21 @@ fn func() -> Option<i32> {
     Some(0)
 }
 
+fn result_func(x: Result<i32, &str>) -> Result<i32, &str> {
+    let _ = x?;
+
+    x?;
+
+    // No warning
+    let y = if let Ok(x) = x {
+        x
+    } else {
+        return Err("some error");
+    };
+
+    Ok(y)
+}
+
 fn main() {
     some_func(Some(42));
     some_func(None);
@@ -123,4 +138,6 @@ fn main() {
     returns_something_similar_to_option(so);
 
     func();
+
+    let _ = result_func(Ok(42));
 }

tests/ui/question_mark.rs

@@ -134,6 +134,23 @@ fn func() -> Option<i32> {
     Some(0)
 }
 
+fn result_func(x: Result<i32, &str>) -> Result<i32, &str> {
+    let _ = if let Ok(x) = x { x } else { return x };
+
+    if x.is_err() {
+        return x;
+    }
+
+    // No warning
+    let y = if let Ok(x) = x {
+        x
+    } else {
+        return Err("some error");
+    };
+
+    Ok(y)
+}
+
 fn main() {
     some_func(Some(42));
     some_func(None);
@@ -153,4 +170,6 @@ fn main() {
     returns_something_similar_to_option(so);
 
     func();
+
+    let _ = result_func(Ok(42));
 }

tests/ui/question_mark.stderr

@@ -100,5 +100,19 @@ LL | |         return None;
 LL | |     }
    | |_____^ help: replace it with: `f()?;`
 
-error: aborting due to 11 previous errors
+error: this if-let-else may be rewritten with the `?` operator
+  --> $DIR/question_mark.rs:138:13
+   |
+LL |     let _ = if let Ok(x) = x { x } else { return x };
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `x?`
+
+error: this block may be rewritten with the `?` operator
+  --> $DIR/question_mark.rs:140:5
+   |
+LL | /     if x.is_err() {
+LL | |         return x;
+LL | |     }
+   | |_____^ help: replace it with: `x?;`
+
+error: aborting due to 13 previous errors