kdb: use kmap_local_page()

Use kmap_local_page() instead of kmap_atomic() which has been deprecated.

Signed-off-by: Zhang Heng <zhangheng@kylinos.cn>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20241223085420.1815930-1-zhangheng@kylinos.cn


Signed-off-by: Daniel Thompson (RISCstar) <danielt@kernel.org>