ioctl routines if we are running with !mpsafenet
- Change un-conditional Giant acquisition around ifpromisc
to occur only if we are running with !mpsafenet
With these locking bits in place, we can now remove the Giant
requirement from BPF, so drop the D_NEEDGIANT device flag.
This change removes Giant acquisitions around BPF device
handlers (read, write, ioctl etc).
MFC after: 1 month
Discussed with: rwatson
5632c9822a