mailmap: correct name for a historical account of Zijun Hu

Correct the name for <zijun_hu@htc.com> from 'zijun_hu' to 'Zijun Hu'.

Link: https://lkml.kernel.org/r/20250620-my_mailmap-v1-2-11ea3db8ba1e@oss.qualcomm.com


Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
Cc: Hans verkuil <hverkuil@xs4all.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>