Missing S: in the "CONTROL GROUP - BLOCK IO CONTROLLER (BLKIO)" entry?

[Zenghui Yu]

Running

# ./scripts/get_maintainer.pl -f block/blk-cgroup.c
Tejun Heo <tj@xxxxxxxxxx> (unknown:CONTROL GROUP - BLOCK IO CONTROLLER 
(BLKIO))
Josef Bacik <josef@xxxxxxxxxxxxxx> (unknown:CONTROL GROUP - BLOCK IO 
CONTROLLER (BLKIO))
Jens Axboe <axboe@xxxxxxxxx> (unknown:CONTROL GROUP - BLOCK IO 
CONTROLLER (BLKIO))
cgroups@xxxxxxxxxxxxxxx (open list:CONTROL GROUP - BLOCK IO CONTROLLER 
(BLKIO))
linux-block@xxxxxxxxxxxxxxx (open list:CONTROL GROUP - BLOCK IO 
CONTROLLER (BLKIO))
linux-kernel@xxxxxxxxxxxxxxx (open list)

shows "unknown" instead of "maintainer" or "supporter".  Is it
intentional?