Fix golint and ruleguard (#8347)

Signed-off-by: yangxuan <xuan.yang@zilliz.com>

internal/datanode/flow_graph_insert_buffer_node.go

@@ -40,11 +40,6 @@ import (
 	"github.com/milvus-io/milvus/internal/proto/schemapb"
 )
 
-const (
-	CollectionPrefix = "/collection/"
-	SegmentPrefix    = "/segment/"
-)
-
 type (
 	// InsertData of storage
 	InsertData = storage.InsertData

internal/indexnode/indexnode.go

@@ -84,11 +84,12 @@ func NewIndexNode(ctx context.Context) (*IndexNode, error) {
 		loopCancel: cancel,
 	}
 	b.UpdateStateCode(internalpb.StateCode_Abnormal)
-	var err error
-	b.sched, err = NewTaskScheduler(b.loopCtx, b.kv)
+	sc, err := NewTaskScheduler(b.loopCtx, b.kv)
 	if err != nil {
 		return nil, err
 	}
+
+	b.sched = sc
 	return b, nil
 }