- Make use of the VM_ALLOC_WIRED flag in the call to vm_page_alloc() in   do_sendfile().  This allows us to rearrange an if statement in order to   avoid doing an unnecesary call to vm_page_lock_queues(), and an attempt   at re-wiring the pages (which were wired in the vm_page_alloc() call).
- Make use of the VM_ALLOC_WIRED flag in the call to vm_page_alloc() in
  do_sendfile().  This allows us to rearrange an if statement in order to
  avoid doing an unnecesary call to vm_page_lock_queues(), and an attempt
  at re-wiring the pages (which were wired in the vm_page_alloc() call).

Reviewed by:	alc, jhb

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