Fix a bug in passing parameters to prepare_user_storage.

Add the serial parameter to prepare_user_storage to avoid
confusion when parsing parameters and passing them around.

Change-Id: Id5516c248401ad50585aa8f6e8b1545a6cded549
diff --git a/main.cpp b/main.cpp
index ea374c5..91e2d98 100644
--- a/main.cpp
+++ b/main.cpp
@@ -98,7 +98,7 @@
     }
 
     // Prepare owner storage
-    e4crypt_prepare_user_storage(nullptr, 0, false);
+    e4crypt_prepare_user_storage(nullptr, 0, 0, false);
 
     cl = new CommandListener();
     ccl = new CryptCommandListener();