Fix for Bug 272357 - rctl.conf(5) resourcing name error

[bcr]

Summary

The patch corrects the man page to replace the nonexisting nproc with maxproc, as outlined in PR272357

Test Plan

1. Apply patch
2. Check the man page
3. Create a testing login class
4. Create a user belonging to that login class
5. Limit the number of processes that this login class can start with the example in the man page
6. Login as that user and start a fork bomb :-)
7. See that it will be cancelled after reaching the maximum number of procs
8. Profit