code review from Josh and Robert

@@ -15,20 +15,20 @@
 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
+     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.
+     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.