staging/lustre/ptlrpc: Remove stray cfs_daemonize comment

Ever since daemonize was removed in 3.18, there are no longer
any flags passed to kthread_run.
Most of the comments were deleted, but this one lingered on
until now.

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>