illumos gate

Build error with gcc 12:

    ../common/ipadm_addr.c: In function 'i_ipadm_op_dhcp':
    ../common/ipadm_addr.c:3229:70: error: the comparison will always evaluate as 'true' for the address of 'ipadm_reqhost' will never be NULL [-Werror=address]
     3229 |                 if (addr->ipadm_af == AF_INET && addr->ipadm_reqhost != NULL &&
              |                                                                          ^~
    In file included from ../common/ipadm_addr.c:62:
    ../common/libipadm_impl.h:99:49: note: 'ipadm_reqhost' declared here
       99 |                         char                    ipadm_reqhost[MAXNAMELEN];
            |                                                    ^~~~~~~~~~~~~
    cc1: all warnings being treated as errors