Clean up PartitionSettings

The PartitionSettings struct contains some data elements that are duplicates
of data elements in the TWPartition class that is contained within the
PartitionsSettings.Part element. We will eliminate this duplication to help
reduce the chances for programming bugs.

Specifically, this fixes problems where the current file system does not
match the backed up file system.

Change-Id: I02f236e72093362050556a2e53a09d1dbb9a269d
diff --git a/gui/action.cpp b/gui/action.cpp
index 073f1a3..a917d2b 100644
--- a/gui/action.cpp
+++ b/gui/action.cpp
@@ -1739,9 +1739,11 @@
 
 	PartitionSettings part_settings;
 	operation_start("Flash Image");
-	DataManager::GetValue("tw_zip_location", part_settings.Restore_Name);
-	DataManager::GetValue("tw_file", part_settings.Backup_FileName);
-	unsigned long long total_bytes = TWFunc::Get_File_Size(part_settings.Restore_Name + "/" + part_settings.Backup_FileName);
+	string path, filename;
+	DataManager::GetValue("tw_zip_location", path);
+	DataManager::GetValue("tw_file", filename);
+	part_settings.Backup_Folder = path + "/" + filename;
+	unsigned long long total_bytes = TWFunc::Get_File_Size(part_settings.Backup_Folder);
 	ProgressTracking progress(total_bytes);
 	part_settings.progress = &progress;
 	part_settings.adbbackup = false;