MAINTAINERS: erofs: update my email address

Old email address will be invalid after a few days, update it
to kernel.org one.

Link: https://lore.kernel.org/r/20210627133229.8025-1-chao@kernel.org


Signed-off-by: Chao Yu <chao@kernel.org>
Acked-by: Gao Xiang <xiang@kernel.org>
Signed-off-by: Gao Xiang <xiang@kernel.org>