LU-6947 ptlrpc: Remove stray comment in ptlrpc_start_pinger

LU-6947 ptlrpc: Remove stray comment in ptlrpc_start_pinger

The comment references cfs_daemonize times when daemonize took
process clone flags. There's no such thing anymore, so
let's drop the comment to not to cause any additional confusion.

Change-Id: I9398f97f604cb70486f6a9b3f9d80360a66c1555
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: http://review.whamcloud.com/15838
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: frank zago <fzago@cray.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>