Documentation: kgdb: Fix a typo

"to into" -> "into"

Reported-by: Sergei Shtylyov <sergei.shtylyov@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/1605519767-25502-1-git-send-email-yangtiezhu@loongson.cn


Signed-off-by: Jonathan Corbet <corbet@lwn.net>