27908 ::gcore breaks sparc build

@@ -174,14 +174,15 @@
 {
         char fname[PATH_MAX];
         struct stat statb;
 
         if (P->state == PS_DEAD) {
-                lwp_info_t *lwp = list_next(&P->core->core_lwp_head);
+                core_info_t *core = P->data;
+                lwp_info_t *lwp = list_next(&core->core_lwp_head);
                 uint_t i;
 
-                for (i = 0; i < P->core->core_nlwp; i++, lwp = list_next(lwp)) {
+                for (i = 0; i < core->core_nlwp; i++, lwp = list_next(lwp)) {
                         if (lwp->lwp_id == lwpid) {
                                 if (lwp->lwp_xregs != NULL)
                                         *xrsize = sizeof (prxregset_t);
                                 else
                                         *xrsize = 0;