don't open-code file_inode()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index 438b5bf..09e7d68 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -94,7 +94,7 @@ static int autofs4_show_options(struct seq_file *m, struct dentry *root)
 		seq_printf(m, ",indirect");
 #ifdef CONFIG_CHECKPOINT_RESTORE
 	if (sbi->pipe)
-		seq_printf(m, ",pipe_ino=%ld", sbi->pipe->f_inode->i_ino);
+		seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino);
 	else
 		seq_printf(m, ",pipe_ino=-1");
 #endif