Added tl_assert() statement on result of VG_(malloc)() calls.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7837 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/exp-drd/drd_error.c b/exp-drd/drd_error.c
index ac496f0..5e92917 100644
--- a/exp-drd/drd_error.c
+++ b/exp-drd/drd_error.c
@@ -79,6 +79,8 @@
   tl_assert(dri);
   tl_assert(dri->addr);
   tl_assert(dri->size > 0);
+  tl_assert(descr1);
+  tl_assert(descr2);
 
   descr1[0] = 0;
   descr2[0] = 0;