[sanitizer] Replace ext2_ ioctls with generic fs_ ioctls.

They are actually the same, but ext2_fs.h header is not available in userspace
with newer kernels.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@184184 91177308-0d34-0410-b5e6-96231b3b80d8