Remove do binding in let form

do binding in let form is not neccessary as let provides an implicit do
form.

src/kibit/rules/control_structures.clj

@@ -18,7 +18,7 @@
   ;; suggest `while` for bindingless loop-recur
   [(loop [] (when ?test . ?exprs (recur)))
    (while ?test . ?exprs)]
-  )
+  [(let ?binding (do . ?exprs)) (let ?binding . ?exprs)])
 
 (comment
   (when (not (pred? x y)) (f x y))

test/kibit/test/control_structures.clj

@@ -16,4 +16,5 @@
     'single-expression '(do single-expression)
     '_ '(when-not true anything)
     '_ '(when false anything)
-    '(when-let [a test] expr) '(if-let [a test] expr nil)))
+    '(when-let [a test] expr) '(if-let [a test] expr nil)
+    '(let [a 1] (println a) a) '(let [a 1] (do (println a) a))))