make the gralloc test linux only

Change-Id: Ib245f7936bbe71b34903172629e09763dd725d80
diff --git a/libgralloc-qsd8k/Android.mk b/libgralloc-qsd8k/Android.mk
index cc92d04..b22541a 100644
--- a/libgralloc-qsd8k/Android.mk
+++ b/libgralloc-qsd8k/Android.mk
@@ -34,11 +34,14 @@
 include $(BUILD_SHARED_LIBRARY)
 
 # Build a host library for testing
+ifeq ($(HOST_OS),linux)
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES :=		\
     gpu.cpp				\
 	pmemalloc.cpp
-	
+
+LOCAL_MODULE_TAGS := tests
 LOCAL_MODULE := libgralloc_qsd8k_host
 LOCAL_CFLAGS:= -DLOG_TAG=\"gralloc-qsd8k\"
 include $(BUILD_HOST_STATIC_LIBRARY)
+endif