UNICHARSET: Use new serialization API

Signed-off-by: Stefan Weil <sw@weilnetz.de>

Author: stweil

src/ccutil/unicharset.h

@@ -354,15 +354,13 @@ class UNICHARSET {
   // Returns true if the operation is successful.
   bool save_to_file(FILE *file) const {
     STRING str;
-    if (!save_to_string(&str)) return false;
-    if (fwrite(&str[0], str.length(), 1, file) != 1) return false;
-    return true;
+    return save_to_string(&str) &&
+           tesseract::Serialize(file, &str[0], str.length());
   }
+
   bool save_to_file(tesseract::TFile *file) const {
     STRING str;
-    if (!save_to_string(&str)) return false;
-    if (file->FWrite(&str[0], str.length(), 1) != 1) return false;
-    return true;
+    return save_to_string(&str) && file->Serialize(&str[0], str.length());
   }
 
   // Saves the content of the UNICHARSET to the given STRING.