rawkv BatchGet memory leak?

[Linzai99]

1. client-go version:
   commit_id is 384feb1
2. pprof heap

heap_pprof.zip

[you06]

I suspect the memory leak is on the recursive stack.

client-go/rawkv/rawkv.go

Lines 804 to 814 in 279dcd5

	if regionErr != nil {
	err := bo.Backoff(retry.BoRegionMiss, errors.New(regionErr.String()))
	if err != nil {
	batchResp.Error = err
	return batchResp
	}
	resp, err = c.sendBatchReq(bo, batch.Keys, options, cmdType)
	batchResp.Response = resp
	batchResp.Error = err
	return batchResp
	}

You can add some debug log here to see if the same region error happens continuously (and from the log, you may find the root cause of this error). Or just tells us how to reproduce this leak.