Really fixes the ub branches

Change-Id: I1d78f4e6c1d8086c2895f6739c3202e9ef74fee2
diff --git a/libbacktrace/Android.build.mk b/libbacktrace/Android.build.mk
index 76c7106..dc73f9f 100644
--- a/libbacktrace/Android.build.mk
+++ b/libbacktrace/Android.build.mk
@@ -60,7 +60,7 @@
     $($(module)_ldlibs_$(build_type)) \
 
 ifeq ($(build_type),target)
-  ifneq ($(module)_libc++,)
+  ifneq ($($(module)_libc++),)
     include external/libcxx/libcxx.mk
   else
     include external/stlport/libstlport.mk