Fixed compilation errors

app/src/main/java/com/sirekanyan/knigopis/common/android/menu/MenuItem.kt

@@ -4,7 +4,7 @@ import android.view.Menu
 import android.view.MenuItem
 
 fun MenuItem.addAll(items: Array<out OptionItem>) {
-    checkNotNull(subMenu) { "submenu is not specified for item $title" }
+    val subMenu = checkNotNull(subMenu) { "submenu is not specified for item $title" }
     items.forEach {
         subMenu.add(Menu.NONE, it.id, Menu.NONE, it.title)
     }

app/src/main/java/com/sirekanyan/knigopis/feature/book/BookView.kt

@@ -130,7 +130,7 @@ class BookViewImpl(
 
     override fun showSaveProgress(isVisible: Boolean) {
         progressMenuItem.isVisible = isVisible
-        progressMenuItem.actionView.show(isVisible)
+        progressMenuItem.actionView?.show(isVisible)
     }
 
     override fun showKeyboard() {