improvement: Don't deserialize again if past attempt failed

Store the state of deserialization such that we only
attemp once when no persisted blobs were found.

Signed-off-by: Kun Yi <kunyi731@gmail.com>
Change-Id: I1d7f605eeff724849429d2ee8fb28b0aa4c05381
diff --git a/binarystore.hpp b/binarystore.hpp
index f07cf7b..3a25581 100644
--- a/binarystore.hpp
+++ b/binarystore.hpp
@@ -142,9 +142,10 @@
   private:
     enum class CommitState
     {
-        Dirty,      // In-memory data might not match persisted data
-        Clean,      // In-memory data matches persisted data
-        CommitError // Error happened during committing
+        Dirty,         // In-memory data might not match persisted data
+        Clean,         // In-memory data matches persisted data
+        Uninitialized, // Cannot find persisted data
+        CommitError    // Error happened during committing
     };
 
     /* Load the serialized data from sysfile if commit state is dirty.