check argument in delete dialog

Author: btimofeev

app/src/main/kotlin/org/emunix/insteadlauncher/ui/dialogs/DeleteGameDialog.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2020 Boris Timofeev <btimofeev@emunix.org>
+ * Copyright (c) 2019-2021 Boris Timofeev <btimofeev@emunix.org>
  * Distributed under the MIT License (license terms are at http://opensource.org/licenses/MIT).
  */
 
@@ -26,11 +26,12 @@ class DeleteGameDialog : DialogFragment() {
 
     override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
         val game = requireArguments().getString("game")
+        require(game != null)
         return MaterialAlertDialogBuilder(requireContext(), R.style.AppTheme_AlertDialogOverlay)
                 .setTitle(R.string.dialog_delete_game_title)
                 .setMessage(R.string.dialog_delete_game_text)
                 .setPositiveButton(R.string.dialog_delete_game_positive_button) { _, _ ->
-                    DeleteGame.start(requireContext().applicationContext, game!!)
+                    DeleteGame.start(requireContext().applicationContext, game)
                 }
                 .setNegativeButton(R.string.dialog_delete_game_negative_button) { dialog, _ ->
                     dialog.cancel()