fix: remove useless "return" at void functions

void functions() returns nothing. So remove useless "return".

found using checkpatch.pl[1]

[1]: https://review.coreboot.org/plugins/gitiles/coreboot/+/refs/heads/master/util/lint/checkpatch.pl



Change-Id: I3daab2abec225a657af48f7d8c215cc554713074
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>