Fix 1 occurrence of named-let-loop-to-for-in-range

This named `let` expression is equivalent to a `for` loop that uses `in-range`.

Author: resyntax-ci[bot]

drracket-core-lib/drracket/private/palaka.rkt

@@ -24,17 +24,15 @@
 (define (draw-palaka dc w h)
   (define alpha (send dc get-alpha))
   (send dc set-pen palaka-color 1 'transparent)
-  (let loop ([dx (- (/ quadrant-size 2))])
-    (when (< dx w)
-      (let loop ([dy (- (/ quadrant-size 2))])
-        (when (< dy h)
-          (send dc set-alpha 1)
-          (send dc set-brush palaka-color 'solid)
-          (send dc draw-rectangle dx dy quadrant-size quadrant-size)
-          (send dc set-brush "white" 'solid)
-          (draw-one-palaka dc dx dy)
-          (loop (+ dy quadrant-size))))
-      (loop (+ dx quadrant-size))))
+  (for ([dx (in-range (- (/ quadrant-size 2)) w quadrant-size)])
+    (let loop ([dy (- (/ quadrant-size 2))])
+      (when (< dy h)
+        (send dc set-alpha 1)
+        (send dc set-brush palaka-color 'solid)
+        (send dc draw-rectangle dx dy quadrant-size quadrant-size)
+        (send dc set-brush "white" 'solid)
+        (draw-one-palaka dc dx dy)
+        (loop (+ dy quadrant-size)))))
   (send dc set-alpha alpha))
 
 (define (draw-one-palaka dc dx dy)