Fixup

diff --git a/src/hb-atomic-private.hh b/src/hb-atomic-private.hh
index b08e90c..e2249e9 100644
--- a/src/hb-atomic-private.hh
+++ b/src/hb-atomic-private.hh

@@ -63,6 +63,7 @@
 }
 
 typedef LONG hb_atomic_int_impl_t;
+#define HB_ATOMIC_INT_IMPL_INIT(V) (V)
 #define hb_atomic_int_impl_add(AI, V)		InterlockedExchangeAdd (&(AI), (V))
 
 #define hb_atomic_ptr_impl_get(P)		(_HBMemoryBarrier (), (void *) *(P))