Make lldb -Werror clean on Windows.

Differential Revision: https://reviews.llvm.org/D25247

llvm-svn: 283344
diff --git a/lldb/source/Plugins/ObjectContainer/Universal-Mach-O/ObjectContainerUniversalMachO.cpp b/lldb/source/Plugins/ObjectContainer/Universal-Mach-O/ObjectContainerUniversalMachO.cpp
index 7d9e30e..a412254 100644
--- a/lldb/source/Plugins/ObjectContainer/Universal-Mach-O/ObjectContainerUniversalMachO.cpp
+++ b/lldb/source/Plugins/ObjectContainer/Universal-Mach-O/ObjectContainerUniversalMachO.cpp
@@ -129,7 +129,7 @@
   s->Indent();
   const size_t num_archs = GetNumArchitectures();
   const size_t num_objects = GetNumObjects();
-  s->Printf("ObjectContainerUniversalMachO, num_archs = %lu, num_objects = %lu",
+  s->Printf("ObjectContainerUniversalMachO, num_archs = %zu, num_objects = %zu",
             num_archs, num_objects);
   uint32_t i;
   ArchSpec arch;