[libcalamares] GS improve load/save

- save should be const
- rename save() to saveJson() for parity with saveYaml()

src/libcalamares/GlobalStorage.cpp

@@ -94,7 +94,7 @@ GlobalStorage::debugDump() const
 }
 
 bool
-GlobalStorage::save( const QString& filename )
+GlobalStorage::saveJson( const QString& filename ) const
 {
     QFile f( filename );
     if ( !f.open( QFile::WriteOnly ) )
@@ -108,7 +108,7 @@ GlobalStorage::save( const QString& filename )
 }
 
 bool
-GlobalStorage::load( const QString& filename )
+GlobalStorage::loadJson( const QString& filename )
 {
     QFile f( filename );
     if ( !f.open( QFile::ReadOnly ) )
@@ -139,7 +139,7 @@ GlobalStorage::load( const QString& filename )
 }
 
 bool
-GlobalStorage::saveYaml( const QString& filename )
+GlobalStorage::saveYaml( const QString& filename ) const
 {
     return CalamaresUtils::saveYaml( filename, m );
 }

src/libcalamares/GlobalStorage.h

@@ -94,7 +94,7 @@ public:
      * and this JSON file will contain that password in-the-only-slightly-
      * obscured form.
      */
-    bool save( const QString& filename );
+    bool saveJson( const QString& filename ) const;
 
     /** @brief Adds the keys from the given JSON file
      *
@@ -103,13 +103,13 @@ public:
      * the global storage. The storage is not cleared first: existing
      * keys will remain; keys that also occur in the JSON file are overwritten.
      */
-    bool load( const QString& filename );
+    bool loadJson( const QString& filename );
 
     /** @brief write as YAML to the given filename
      *
      * See also save(), above.
      */
-    bool saveYaml( const QString& filename );
+    bool saveYaml( const QString& filename ) const;
 
     /** @brief reads settings from the given filename
      *

src/modules/preservefiles/PreserveFiles.cpp

@@ -138,7 +138,7 @@ PreserveFiles::exec()
         }
         if ( it.type == ItemType::Config )
         {
-            if ( Calamares::JobQueue::instance()->globalStorage()->save( dest ) )
+            if ( Calamares::JobQueue::instance()->globalStorage()->saveJson( dest ) )
             {
                 cWarning() << "Could not write config for" << dest;
             }