Test the correct return code from call to cryptfs.

This was broken in commit dd519fac9b79f36a27909149a90fce4321ed1c20
(certainly by mistake), in which Integer.parseInt(tokens[1]) was
errornously replaced with event.getCode().

Change-Id: Ic5af5a2ec5f321da21a4a5db25f6908462f6cae8
diff --git a/services/java/com/android/server/MountService.java b/services/java/com/android/server/MountService.java
index 1dd6bca..a32e9f5 100644
--- a/services/java/com/android/server/MountService.java
+++ b/services/java/com/android/server/MountService.java
@@ -1792,7 +1792,7 @@
         try {
             event = mConnector.execute("cryptfs", "checkpw", password);
 
-            final int code = event.getCode();
+            final int code = Integer.parseInt(event.getMessage());
             if (code == 0) {
                 // Decrypt was successful. Post a delayed message before restarting in order
                 // to let the UI to clear itself