erofs: get rid of label `restart_now'

Simplify this part of code. No logic changes.

Link: https://lore.kernel.org/r/20220529055425.226363-3-xiang@kernel.org


Acked-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>