Consider $(use_clang) when building libc_thread_atexit_impl module

Change-Id: Ia369d94979f418198a2ee891385942d9bc5604d7
diff --git a/libc/Android.mk b/libc/Android.mk
index 2d97f35..0248c5e 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -1053,6 +1053,7 @@
 LOCAL_CPPFLAGS := $(libc_common_cppflags) -Wold-style-cast
 LOCAL_C_INCLUDES := $(libc_common_c_includes)
 LOCAL_MODULE := libc_thread_atexit_impl
+LOCAL_CLANG := $(use_clang)
 LOCAL_ADDITIONAL_DEPENDENCIES := $(libc_common_additional_dependencies)
 LOCAL_CXX_STL := none
 LOCAL_SYSTEM_SHARED_LIBRARIES :=