fix incorrect doc

crates/bevy_ecs/src/query/access.rs

@@ -216,7 +216,7 @@ impl<T: SparseSetIndex> FilteredAccess<T> {
         self.without.union_with(&access.without);
     }
 
-    /// Returns `true` if the access can read all elements in the collection.
+    /// Sets the underlying unfiltered access as being able to read all elements in the collection.
     pub fn read_all(&mut self) {
         self.access.read_all();
     }