[IRDA]: Move ircomm_tty_line_info() under #ifdef CONFIG_PROC_FS

The function in question is called only from ircomm_tty_read_proc,
which is under this option. Move this helper to the same place.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>