10132 smatch fixes for MDB
Reviewed by: Andy Fiddaman <andy@omniosce.org>

*** 18,28 ****
   *
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 2013 by Delphix. All rights reserved.
!  * Copyright (c) 2012 Joyent, Inc. All rights reserved.
   * Copyright (c) 2013 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
   */
  /*
   * This file contains all of the interfaces for mdb's tab completion engine.
   * Currently some interfaces are private to mdb and its internal implementation,
--- 18,28 ----
   *
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 2013 by Delphix. All rights reserved.
!  * Copyright (c) 2018, Joyent, Inc.
   * Copyright (c) 2013 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
   */
  /*
   * This file contains all of the interfaces for mdb's tab completion engine.
   * Currently some interfaces are private to mdb and its internal implementation,
*** 401,412 ****
  
          /*
           * If we have a match set, then we want to verify that we actually match
           * it.
           */
!         if (mcp->mtc_base != NULL &&
!             strncmp(name, mcp->mtc_base, strlen(mcp->mtc_base)) != 0)
                  return;
  
          v = mdb_nv_lookup(&mcp->mtc_nv, name);
          if (v != NULL)
                  return;
--- 401,411 ----
  
          /*
           * If we have a match set, then we want to verify that we actually match
           * it.
           */
!         if (strncmp(name, mcp->mtc_base, strlen(mcp->mtc_base)) != 0)
                  return;
  
          v = mdb_nv_lookup(&mcp->mtc_nv, name);
          if (v != NULL)
                  return;
*** 441,457 ****
  }
  
  const char *
  mdb_tab_match(mdb_tab_cookie_t *mcp)
  {
!         size_t blen;
! 
!         if (mcp->mtc_base == NULL)
!                 blen = 0;
!         else
!                 blen = strlen(mcp->mtc_base);
!         return (mcp->mtc_match + blen);
  }
  
  void
  mdb_tab_setmbase(mdb_tab_cookie_t *mcp, const char *base)
  {
--- 440,450 ----
  }
  
  const char *
  mdb_tab_match(mdb_tab_cookie_t *mcp)
  {
!         return (mcp->mtc_match + strlen(mcp->mtc_base));
  }
  
  void
  mdb_tab_setmbase(mdb_tab_cookie_t *mcp, const char *base)
  {