升级了安卓ndk从r14到r15以后，项目无法编译成功。报错
undefined reference to `major'
谷歌以后发现
https://github.com/axboe/fio/issues/367
https://github.com/android-ndk/ndk/issues/398
坑爹的升级
Android's had <sys/sysmacros.h> for a long time, but in NDK r15 we're likely to have to remove the transitive include from <sys/types.h>
于是
#include <sys/sysmacros.h>
解决了这个问题
