Auto merge of #2089 - KentaTada:add-selinuxfs, r=JohnTitor
Auto merge of #2089 - KentaTada:add-selinuxfs, r=JohnTitor

Add definition of SELINUX_MAGIC

This commit adds the definition of SELINUX_MAGIC.

rust-lang/libc,rust-lang/libc,rust-lang/libc