machine/store: modify connect() return value

Modified fmt.Errorf() in connect() function.
When executing `kraft ps` in user state, error reporting would have a redundant prompt message.
Distinguished between basic errors, and the added annotated errors.

Signed-off-by: Zeyu Li <mr.lizeyu@outlook.com>

machine/store.go

@@ -38,10 +38,10 @@ import (
 	"path/filepath"
 	"time"
 
+	"github.com/dgraph-io/badger/v3"
+	"github.com/juju/errors"
 	"kraftkit.sh/config"
 	"kraftkit.sh/internal/retrytimeout"
-
-	"github.com/dgraph-io/badger/v3"
 )
 
 type MachineStore struct {
@@ -109,12 +109,12 @@ func (ms *MachineStore) connect() error {
 		var err error
 		db, err = badger.Open(ms.bopts)
 		if err != nil {
-			return fmt.Errorf("could not open machine store: %v", err)
+			return errors.Errorf("%v", err)
 		}
 
 		return nil
 	}); err != nil {
-		return fmt.Errorf("could not open machine store: %v", err)
+		return errors.Annotate(err, "could not open machine store")
 	}
 
 	ms.db = db