fix compilation

weed/server/master_server_handlers_admin.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"github.com/chrislusf/seaweedfs/weed/pb"
+	"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
 	"math/rand"
 	"net/http"
 	"strconv"
@@ -81,7 +82,9 @@ func (ms *MasterServer) volumeGrowHandler(w http.ResponseWriter, r *http.Request
 		if ms.Topo.AvailableSpaceFor(option) < int64(count*option.ReplicaPlacement.GetCopyCount()) {
 			err = fmt.Errorf("only %d volumes left, not enough for %d", ms.Topo.AvailableSpaceFor(option), count*option.ReplicaPlacement.GetCopyCount())
 		} else {
-			count, err = ms.vg.GrowByCountAndType(ms.grpcDialOption, count, option, ms.Topo)
+			var newVidLocations []*master_pb.VolumeLocation
+			newVidLocations, err = ms.vg.GrowByCountAndType(ms.grpcDialOption, count, option, ms.Topo)
+			count = len(newVidLocations)
 		}
 	} else {
 		err = fmt.Errorf("can not parse parameter count %s", r.FormValue("count"))