Timeout in seekLeaderStore is not limited

[marsishandsome]

Here is a SlogLog generated by the case kill az with pd leader.

{"start":"21:12:36.806","end":"21:12:42.299","duration":"5493ms","error":"retry is exhausted.","func":"get","region":"{Region[12358] ConfVer[547] Version[20] Store[20] KeyRange[indexInfo_:_pf01_:_APD01_:_3500770017512150000]:[indexInfo_:_pf01_:_APD01_:_3501970010589630000]}","key":"indexInfo_:_pf01_:_APD01_:_3501910019979570000","spans":[{"name":"getRegionByKey","start":"21:12:36.806","end":"21:12:36.806","duration":"0ms"},{"name":"callWithRetry tikvpb.Tikv/RawGet","start":"21:12:36.806","end":"21:12:42.298","duration":"5492ms"},{"name":"gRPC tikvpb.Tikv/RawGet","start":"21:12:36.806","end":"21:12:36.956","duration":"150ms"},{"name":"backoff BoCheckTimeout","start":"21:12:36.956","end":"21:12:36.956","duration":"0ms"},{"name":"backoff BoCheckTimeout","start":"21:12:36.956","end":"21:12:36.956","duration":"0ms"},{"name":"seekLeaderStore","start":"21:12:36.956","end":"21:12:42.298","duration":"5342ms"},{"name":"backoff BoRegionMiss","start":"21:12:42.298","end":"N/A","duration":"N/A"}]}

Timeout in seekLeaderStore is not limited

{
            "name":"seekLeaderStore",
            "start":"21:12:36.956",
            "end":"21:12:42.298",
            "duration":"5342ms"
        }