- Fix argument list after 271387.
- While here fix typo.

Submitted by:	markj
Initialize variables before resource_int_value().

Submitted by:	Dmitry Luhtionov <dmitryluhtionov@gmail.com>
- Provide a sleepable lock to protect against ioctl() vs ioctl() races.
- Use the new lock to protect against simultaneous DIOCSTART and/or
  DIOCSTOP ioctls.

Reported & tested by:	jmallett
Sponsored by:		Nginx, Inc.