libdw: Sanity check end of section against cu_data () of die->cu.

A Dwarf_CU can come from either the debug_info compile unit or a
debug_type type unit section. Use the correct one for sanity checking
whether we have a truncated section.
diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 0b17461..8febd42 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,8 @@
+2011-04-26  Mark Wielaard  <mjw@redhat.com>
+
+	* dwarf_child (dwarf_child): Sanity check end of section against
+	cu_data () of die->cu.
+
 2011-03-22  Mark Wielaard  <mjw@redhat.com>
 
 	* dwarf.h: Add DW_TAG_GNU_call_site,