fix: make sure atomic 64bit fields are 64bit aligned

Otherwise, this won't work on 32bit ARM.

blockstore/badger/blockstore.go

@@ -84,11 +84,11 @@ const (
 // operation calls after Close() has returned, but it may not happen for
 // operations in progress. Those are likely to fail with a different error.
 type Blockstore struct {
-	DB *badger.DB
-
-	// state is guarded by atomic.
+	// state is accessed atomically
 	state int64
 
+	DB *badger.DB
+
 	prefixing bool
 	prefix    []byte
 	prefixLen int