[skip ci] Add comment for getSegmentIDsByVChannel (#11101)

Signed-off-by: Nbigsheeper <yihao.dai@zilliz.com>

internal/querynode/collection_replica.go

@@ -75,6 +75,7 @@ type ReplicaInterface interface {
 	getPartitionNum() int
 	// getSegmentIDs returns segment ids
 	getSegmentIDs(partitionID UniqueID) ([]UniqueID, error)
+	// getSegmentIDsByVChannel returns segment ids which virtual channel is vChannel
 	getSegmentIDsByVChannel(partitionID UniqueID, vChannel Channel) ([]UniqueID, error)
 
 	// segment