proc: fix proc_kill_inodes to kill dentries on all proc superblocks

It appears we overlooked support for removing generic proc files
when we added support for multiple proc super blocks.  Handle
that now.

[akpm@linux-foundation.org: coding-style cleanups]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/root.c b/fs/proc/root.c
index ec9cb3b..1f86bb8 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -98,7 +98,7 @@
 	put_pid_ns(ns);
 }
 
-static struct file_system_type proc_fs_type = {
+struct file_system_type proc_fs_type = {
 	.name		= "proc",
 	.get_sb		= proc_get_sb,
 	.kill_sb	= proc_kill_sb,