If cpufreq_register_notifier() fails, we have to remove the port added by
sci_probe_single(), which is not done by sci_cleanup_single().

Else the serial port stays active from the point of view of the serial
subsystem, and it may crash when userspace getty is started, or when the
loadable driver module is unloaded.

This was introduced by commit 6dae1421
("serial: sh-sci: Fix probe error paths").
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>