fix #29612968

Sector address of all bios in a single request should be guaranteed to
be contiguous, except for DISCARD request. We could get the whole sector
range of the request by blk_rq_pos() and blk_rq_bytes() for normal read
/write requests, but here we still print the sector range of every bio
for code simpility. Since it is a low frequency operation, this design
will lead to no performance penalty.

Besides squash the 'if(bio)' and 'while(1)' into one single
'while(bio)'.
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>