procfs: move dropping pde and pid from ->evict_inode() to ->free_inode()

that keeps both around until struct inode is freed, making access
to them safe from rcu-pathwalk

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2 files changed