[PATCH -mm] proc: fixup comment

[Alexey Dobriyan]

Document what ->pde_unload_lock actually does.

Signed-off-by: Alexey Dobriyan <adobri...@gmail.com>
---

 fs/proc/internal.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -38,7 +38,8 @@ struct proc_dir_entry {
        atomic_t in_use;
        atomic_t count;         /* use count */
        struct list_head pde_openers;   /* who did ->open, but not ->release */
-       spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
+       /* protects ->pde_openers and all struct pde_opener instances */
+       spinlock_t pde_unload_lock;
        struct completion *pde_unload_completion;
        const struct inode_operations *proc_iops;
        const struct file_operations *proc_fops;