scsi: core: docs: Update notes about scsi_times_out

Most importantly: eh_timed_out() is not limited by scmd->allowed, and can
reset timer forever.

Fixes: c829c394 ("[SCSI] FC transport : Avoid device offline cases by stalling aborts until device unblocked")
Link: https://lore.kernel.org/r/20220219001601.3534043-1-khazhy@google.com


Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>