misc: Convert daemon () to GNU coding style

This is nicer, and is going to be required for the following changes
to reasonably stay within the 79 column limit.

No functional change.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Message-Id: <20230419160207.65988-2-bugaevc@gmail.com>