illumos gate

With NULL pointer, errors are reported while building ip module:

    ../../common/inet/sctp/sctp.c: In function 'sctp_find_next_tq':
    ../../common/inet/sctp/sctp.c:1791:19: error: comparison between pointer and integer [-Werror]
           TQ_NOSLEEP) != NULL) {
                       ^~
    ../../common/inet/sctp/sctp.c:1806:63: error: comparison between pointer and integer [-Werror]
      if (taskq_dispatch(tq, sctp_process_recvq, sctp, TQ_NOSLEEP) != NULL) {
                                                                   ^~
    ../../common/inet/ip/ip_attr.c:1393:33: error: comparison between pointer and integer [-Werror]
      } else if (idl_txl->txl_cookie != NULL &&
                                     ^~

    ../../common/inet/ip/ip_ire.c: In function 'ire_init_v4':
    ../../common/inet/ip/ip_ire.c:546:12: error: comparison between pointer and integer [-Werror]
      if (error != NULL)
                ^~

    ../../common/inet/ip/ip6_ire.c:129:12: error: comparison between pointer and integer [-Werror]
      if (error != NULL)
                ^~

    ../../common/sys/null.h:32:14: error: passing argument 2 of 'ire_ftable_lookup_v4' makes integer from pointer without a cast [-Werror=int-conversion]
     #define NULL ((void *)0)
                  ^
    ../../common/inet/ip/ip.c:15107:35: note: in expansion of macro 'NULL'
      ire = ire_ftable_lookup_v4(addr, NULL, NULL, IRE_LOCAL | IRE_LOOPBACK,
                                       ^~~~
    In file included from ../../common/inet/ip/ip.c:90:0:
    ../../common/inet/ip_ire.h:177:15: note: expected 'ipaddr_t {aka unsigned int}' but argument is of type 'void *'
     extern ire_t *ire_ftable_lookup_v4(ipaddr_t, ipaddr_t, ipaddr_t, int,
                   ^~~~~~~~~~~~~~~~~~~~
    In file included from ../../common/sys/param.h:48:0,
                     from ../../common/sys/t_lock.h:38,
                     from ../../common/sys/thread.h:36,
                     from ../../common/sys/poll.h:101,
                     from ../../common/sys/stream.h:42,
                     from ../../common/inet/ip/ip.c:31:
    ../../common/sys/null.h:32:14: error: passing argument 3 of 'ire_ftable_lookup_v4' makes integer from pointer without a cast [-Werror=int-conversion]
     #define NULL ((void *)0)
                  ^
    ../../common/inet/ip/ip.c:15107:41: note: in expansion of macro 'NULL'
      ire = ire_ftable_lookup_v4(addr, NULL, NULL, IRE_LOCAL | IRE_LOOPBACK,
                                             ^~~~
    In file included from ../../common/inet/ip/ip.c:90:0:
    ../../common/inet/ip_ire.h:177:15: note: expected 'ipaddr_t {aka unsigned int}' but argument is of type 'void *'
     extern ire_t *ire_ftable_lookup_v4(ipaddr_t, ipaddr_t, ipaddr_t, int,
                   ^~~~~~~~~~~~~~~~~~~~

    ../../common/inet/ip/ip_netinfo.c:1095:10: error: return makes integer from pointer without a cast [-Werror=int-conversion]
       return (NULL);
              ^
    ../../common/inet/ip/ip6.c:2119:25: note: in expansion of macro 'NULL'
       nce = ire_to_nce(ire, NULL, firsthop);
                             ^~~~
    In file included from ../../common/inet/ip/ip6.c:84:0:
    ../../common/inet/ip_ire.h:302:15: note: expected 'ipaddr_t {aka unsigned int}' but argument is of type 'void *'
     extern nce_t *ire_to_nce(ire_t *, ipaddr_t, const in6_addr_t *);
                   ^~~~~~~~~~

    cc1: all warnings being treated as errors