vfs: switch ->show_path() to struct dentry *

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 6d4583d..8f8304b 100644
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -131,7 +131,7 @@
 	seq_printf(m, "%i %i %u:%u ", r->mnt_id, r->mnt_parent->mnt_id,
 		   MAJOR(sb->s_dev), MINOR(sb->s_dev));
 	if (sb->s_op->show_path)
-		err = sb->s_op->show_path(m, mnt);
+		err = sb->s_op->show_path(m, mnt->mnt_root);
 	else
 		seq_dentry(m, mnt->mnt_root, " \t\n\\");
 	if (err)