drd: Build fix for ENABLE_DRD_CONSISTENCY_CHECKS

From: Ivo Raisr <ivosh@ivosh.net>


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13863 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/drd/drd_thread.c b/drd/drd_thread.c
index d07ca8b..2c2e96c 100644
--- a/drd/drd_thread.c
+++ b/drd/drd_thread.c
@@ -255,16 +255,16 @@
 {
    Segment* p;
 
-   for (p = ti->first; p; p = p->next) {
-      if (p->next && p->next->prev != p)
+   for (p = ti->sg_first; p; p = p->thr_next) {
+      if (p->thr_next && p->thr_next->thr_prev != p)
          return False;
-      if (p->next == 0 && p != ti->last)
+      if (p->thr_next == 0 && p != ti->sg_last)
          return False;
    }
-   for (p = ti->last; p; p = p->prev) {
-      if (p->prev && p->prev->next != p)
+   for (p = ti->sg_last; p; p = p->thr_prev) {
+      if (p->thr_prev && p->thr_prev->thr_next != p)
          return False;
-      if (p->prev == 0 && p != ti->first)
+      if (p->thr_prev == 0 && p != ti->sg_first)
          return False;
    }
    return True;