no need to save this function within a variable

Author: yaacovCR

src/execution/collectFields.ts

@@ -167,11 +167,11 @@ function buildSelectionSetVisitor(
 ) => void {
   const visitedFragmentNames = new Set<string>();
 
-  const selectionSetVisitor = (
+  function selectionSetVisitor(
     selectionSet: SelectionSetNode,
     deferUsage?: DeferUsage,
     fragmentVariableValues?: VariableValues,
-  ): void => {
+  ): void {
     for (const selection of selectionSet.selections) {
       switch (selection.kind) {
         case Kind.FIELD: {
@@ -340,7 +340,7 @@ function buildSelectionSetVisitor(
       }
       return true;
     }
-  };
+  }
 
   /**
    * Determines if a fragment is applicable to the given type.