merge-blobs.c: remove implicit dependency on the_index

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/merge-tree.c

@@ -76,7 +76,7 @@ static void *result(struct merge_list *entry, unsigned long *size)
 	their = NULL;
 	if (entry)
 		their = entry->blob;
-	return merge_blobs(path, base, our, their, size);
+	return merge_blobs(&the_index, path, base, our, their, size);
 }
 
 static void *origin(struct merge_list *entry, unsigned long *size)