commit 855515a6 upstream.

Fix reporting of overrun errors, which are not associated with a
character. Instead insert a null character and report only once.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>