[ghex] hex-doc: Fix assertion check in hex_document_write_to_file_async

[Logan Rathbone <larathbone src gnome org>]

commit 33408851ea228c6bbc344cdc444af46240cdf121
Author: Logan Rathbone <poprocks gmail com>
Date:   Sat Jun 25 12:38:36 2022 -0400

    hex-doc: Fix assertion check in hex_document_write_to_file_async
    
    Fixes effective regression from ghex-42 to master on save-as operations
    for new files, since the async function had the wrong assertion check,
    but nothing was using it before so it wasn't noticed.

 src/hex-document.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/hex-document.c b/src/hex-document.c
index dc40839..465cfe0 100644
--- a/src/hex-document.c
+++ b/src/hex-document.c
@@ -959,7 +959,7 @@ hex_document_write_to_file_async (HexDocument *doc,
 {
        GTask *doc_task;
 
-       g_return_if_fail (G_IS_FILE (doc->file));
+       g_return_if_fail (G_IS_FILE (file));
 
        doc_task = g_task_new (doc, cancellable, callback, user_data);