Generating more simple construct instead of "let" in some cases

idea/testData/intentions/loopToCallChain/firstOrNull_safeDotExpression.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+fun foo(list: List<String?>) {
+    var result: String? = null
+    <caret>for (s in list) {
+        if (s != "") {
+            result = s?.substring(1)
+            break
+        }
+    }
+}