code review from Josh and Robert

*** 15,34 ****
  PARAMETERS
       vmp     The vmem arena to which the span should be added.
  
       vaddr   The base address of the span to add.
  
!      size    The size of the span to add
  
       vmflag  Flags affecting the allocation of the span to add.
  
  DESCRIPTION
       The vmem_add() function adds size bytes starting at vaddr to a vmem arena
       from which future calls to vmem_alloc() may allocate.
  
!      VM_SLEEP or VM_NOSLEEP must be specified, and indicate whether the
!      addition may block.
  
  CONTEXT
       This function can be called from either user or kernel context.  If the
       VM_NOSLEEP flag is specified, it may also be called from interrupt
       context.
--- 15,34 ----
  PARAMETERS
       vmp     The vmem arena to which the span should be added.
  
       vaddr   The base address of the span to add.
  
!      size    The size of the span to add.
  
       vmflag  Flags affecting the allocation of the span to add.
  
  DESCRIPTION
       The vmem_add() function adds size bytes starting at vaddr to a vmem arena
       from which future calls to vmem_alloc() may allocate.
  
!      VM_SLEEP or VM_NOSLEEP must be specified in vmflag, and indicate whether
!      the addition may block.
  
  CONTEXT
       This function can be called from either user or kernel context.  If the
       VM_NOSLEEP flag is specified, it may also be called from interrupt
       context.