Fix a Valgrind integration flaw.

Fix a Valgrind integration flaw that caused Valgrind warnings about
reads of uninitialized memory in internal zero-initialized data
structures (relevant to tcache and prof code).
diff --git a/ChangeLog b/ChangeLog
index 3661427..9b51fd5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -9,8 +9,11 @@
 * 3.4.1 (XXX)
 
   Bug fixes:
-  - Fix a Valgrind integration flaw that caused Valgrind warnings about reads of
-    uninitialized memory in arena chunk headers.
+  - Fix Valgrind integration flaws that caused Valgrind warnings about reads of
+    uninitialized memory in:
+    + arena chunk headers
+    + internal zero-initialized data structures (relevant to tcache and prof
+      code)
   - Preserve errno during the first allocation.  A readlink(2) call during
     initialization fails unless /etc/malloc.conf exists, so errno was typically
     set during the first allocation prior to this fix.