fix 2nd target clang prebuilt paths

Change-Id: I4c196221bd377e30bbff1aafa265952e29c85cb5
diff --git a/core/clang/TARGET_x86.mk b/core/clang/TARGET_x86.mk
index 0178093..0f530b5 100644
--- a/core/clang/TARGET_x86.mk
+++ b/core/clang/TARGET_x86.mk
@@ -3,7 +3,7 @@
 
 CLANG_CONFIG_x86_TARGET_TRIPLE := i686-linux-android
 CLANG_CONFIG_x86_TARGET_TOOLCHAIN_PREFIX := \
-  $(TARGET_TOOLCHAIN_ROOT)/x86_64-linux-android/bin
+  $($(clang_2nd_arch_prefix)TARGET_TOOLCHAIN_ROOT)/x86_64-linux-android/bin
 
 CLANG_CONFIG_x86_TARGET_EXTRA_ASFLAGS := \
   $(CLANG_CONFIG_EXTRA_ASFLAGS) \