11894 zonecfg export should quote strings

*** 21,30 ****
--- 21,31 ----
  
  /*
   * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
   * Copyright 2014 Gary Mills
+  * Copyright 2019 Joyent, Inc.
   */
  
  /*
   * zonecfg is a lex/yacc based command interpreter used to manage zone
   * configurations.  The lexer (see zonecfg_lex.l) builds up tokens, which
*** 1825,1835 ****
          char *quote_str;
  
          if (strlen(prop_id) == 0)
                  return;
          quote_str = quoteit(prop_id);
!         (void) fprintf(of, "%s %s=%s\n", cmd_to_str(CMD_SET),
              pt_to_str(prop_num), quote_str);
          free(quote_str);
  }
  
  void
--- 1826,1836 ----
          char *quote_str;
  
          if (strlen(prop_id) == 0)
                  return;
          quote_str = quoteit(prop_id);
!         (void) fprintf(of, "%s %s=\"%s\"\n", cmd_to_str(CMD_SET),
              pt_to_str(prop_num), quote_str);
          free(quote_str);
  }
  
  void