o Make pv_maxchunks no less than maxproc.  This helps to survive a forkbomb explosion.
o Make pv_maxchunks no less than maxproc.  This helps to survive a
forkbomb explosion.

Reviewed by:	alc
Security:	local DoS
X-MFC atfer:	RELENG_6 is not affected due to a different pv_entry
		allocation code.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase