speakup: Avoid crash on very long word

mainline inclusion
from mainline-v6.9-rc5
commit c8d2f34ea96ea3bce6ba2535f867f0d4ee3b22e1
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9L5L5
CVE: CVE-2024-26994

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c8d2f34ea96ea3bce6ba2535f867f0d4ee3b22e1



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In case a console is set up really large and contains a really long word
(> 256 characters), we have to stop before the length of the word buffer.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Fixes: c6e3fd22 ("Staging: add speakup to the staging directory")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240323164843.1426997-1-samuel.thibault@ens-lyon.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:
	drivers/staging/speakup/main.c
[file was copy from drivers/staging/speakup/main.c to drivers/accessibility/speakup/main.c]
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>