Fix convert unary operator to function call

#KT-25501 Fixed

idea/testData/intentions/operatorToFunction/notApplicablePostfixPlusPlusInNestedIfExpression.kt

@@ -0,0 +1,9 @@
+// IS_APPLICABLE: false
+fun foo() {
+    var a = 0
+    val b = if (false) {
+        if (true) {
+            a++<caret>
+        } else a
+    } else a
+}