illumos gate

NULL pointer errors:

    ../../common/io/eventfd.c: In function 'eventfd_open':
    ../../common/io/eventfd.c:72:10: error: return makes integer from pointer without a cast [-Werror=int-conversion]
       return (NULL);
              ^
    In file included from ../../common/sys/param.h:48:0,
                     from ../../common/sys/t_lock.h:38,
                     from ../../common/sys/map.h:35,
                     from ../../common/sys/ddi.h:37,
                     from ../../common/io/eventfd.c:21:
    ../../common/io/eventfd.c: In function 'eventfd_attach':
    ../../common/sys/null.h:32:14: error: passing argument 6 of 'ddi_create_minor_node' makes integer from pointer without a cast [-Werror=int-conversion]
     #define NULL ((void *)0)
                  ^
    ../../common/io/eventfd.c:322:39: note: in expansion of macro 'NULL'
          EVENTFDMNRN_EVENTFD, DDI_PSEUDO, NULL) == DDI_FAILURE) {
                                           ^~~~
    In file included from ../../common/io/eventfd.c:22:0:
    ../../common/sys/sunddi.h:1564:1: note: expected 'int' but argument is of type 'void *'
     ddi_create_minor_node(dev_info_t *dip, char *name, int spec_type,
     ^~~~~~~~~~~~~~~~~~~~~
    cc1: all warnings being treated as errors