Fx a type from r271817;  it's IFCOUNTER_* not IFNET_*.
Allow more commands to pass persistent reservation according to SPC-4 r37.
Don't use nvl in case of a failure.

Reported by:	Coverity
CID:		1238922
Mechanically convert to if_inc_counter().
Fix typo.

Submitted by:	jkim
Merge remote-tracking branch 'freebsd/master' into hardened/current/userlandenhanced