Update src/query.md

Co-authored-by: Boxy <rust@boxyuwu.dev>

Author: xizheyin

src/query.md

@@ -169,9 +169,10 @@ Suppose you want to add a new query called `fubar`. You would:
     ```
 2. Register it in the `provide` function:
     ```rust,ignore
-    pub fn provide(providers: &mut rustc_middle::util::Providers) {
-        providers.queries.fubar = fubar;
-    }
+    pub fn provide(providers: &mut Providers) {
+        *providers = Providers {
+            fubar,
+            ..*providers
     ```
 
 ### How queries interact with external crate metadata