Move libutils over to pthread_gettid_np.

Bug: 17476168
Change-Id: I934d93a023eb00e036ed3cee8c52efaeb17b8915
diff --git a/libutils/Android.mk b/libutils/Android.mk
index 0c8625c..b55e635 100644
--- a/libutils/Android.mk
+++ b/libutils/Android.mk
@@ -93,8 +93,7 @@
 LOCAL_CFLAGS += -Werror
 
 LOCAL_C_INCLUDES += \
-		bionic/libc \
-		external/zlib
+	external/zlib
 
 LOCAL_STATIC_LIBRARIES := \
 	libcutils