graph/db: thread context through MarkEdgeZombie

graph/db/sql_store.go

@@ -1783,11 +1783,9 @@ func (s *SQLStore) FilterChannelRange(ctx context.Context, startHeight,
 // marked as zombies outside the normal pruning cycle.
 //
 // NOTE: part of the Store interface.
-func (s *SQLStore) MarkEdgeZombie(chanID uint64,
+func (s *SQLStore) MarkEdgeZombie(ctx context.Context, chanID uint64,
 	pubKey1, pubKey2 [33]byte) error {
 
-	ctx := context.TODO()
-
 	s.cacheMu.Lock()
 	defer s.cacheMu.Unlock()