10096 kstat update routines shouldn't check for NULL kstat

*** 20,29 ****
--- 20,30 ----
   */
  /*
   * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2013 by Delphix. All rights reserved.
   * Copyright 2014, OmniTI Computer Consulting, Inc. All rights reserved.
+  * Copyright (c) 2018, Joyent, Inc.
   */
  /* Copyright (c) 1990 Mentat Inc. */
  
  #include <sys/types.h>
  #include <sys/stream.h>
*** 5070,5080 ****
          rawip_named_kstat_t *rawipkp;
          netstackid_t    stackid = (netstackid_t)(uintptr_t)ksp->ks_private;
          netstack_t      *ns;
          icmp_stack_t    *is;
  
!         if ((ksp == NULL) || (ksp->ks_data == NULL))
                  return (EIO);
  
          if (rw == KSTAT_WRITE)
                  return (EACCES);
  
--- 5071,5081 ----
          rawip_named_kstat_t *rawipkp;
          netstackid_t    stackid = (netstackid_t)(uintptr_t)ksp->ks_private;
          netstack_t      *ns;
          icmp_stack_t    *is;
  
!         if (ksp->ks_data == NULL)
                  return (EIO);
  
          if (rw == KSTAT_WRITE)
                  return (EACCES);