docs, kprobes: Update email address of Masami Hiramatsu

According to the latest authorship and Signed-off-by:

  Masami Hiramatsu (Google) <mhiramat@kernel.org>

Masami Hiramatsu is working at Google, so the current email @redhat.com
is out of date, it is better to use the email @kernel.org.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20231219062330.22813-2-yangtiezhu@loongson.cn