graph/db: remove KVStore fall-back

Now that SQLStore fully implements V1Store, we no longer need the
KVStore fall-back.

graph/db/sql_store.go

@@ -175,10 +175,6 @@ type SQLStore struct {
 
 	srcNodes  map[ProtocolVersion]*srcNodeInfo
 	srcNodeMu sync.Mutex
-
-	// Temporary fall-back to the KVStore so that we can implement the
-	// interface incrementally.
-	*KVStore
 }
 
 // A compile-time assertion to ensure that SQLStore implements the V1Store
@@ -194,7 +190,7 @@ type SQLStoreConfig struct {
 
 // NewSQLStore creates a new SQLStore instance given an open BatchedSQLQueries
 // storage backend.
-func NewSQLStore(cfg *SQLStoreConfig, db BatchedSQLQueries, kvStore *KVStore,
+func NewSQLStore(cfg *SQLStoreConfig, db BatchedSQLQueries,
 	options ...StoreOptionModifier) (*SQLStore, error) {
 
 	opts := DefaultOptions()
@@ -210,7 +206,6 @@ func NewSQLStore(cfg *SQLStoreConfig, db BatchedSQLQueries, kvStore *KVStore,
 	s := &SQLStore{
 		cfg:         cfg,
 		db:          db,
-		KVStore:     kvStore,
 		rejectCache: newRejectCache(opts.RejectCacheSize),
 		chanCache:   newChannelCache(opts.ChannelCacheSize),
 		srcNodes:    make(map[ProtocolVersion]*srcNodeInfo),