jail: Fix redoing ip restricting

prison_ip_restrict() is called in loop FOREACH_PRISON_DESCENDANT_LOCKED.
While under low memory, it is still possible that in subsequent rounds
prison_ip_restrict() succeed and redo_ip[46] flip over from true to
false, thus leave some prisons's IPv[46] addresses unrestricted.

Reviewed by: jamie
Fixes: 8bce8d28abe6 jail: Avoid multipurpose return value of function prison_ip_restrict()
Differential Revision: https://reviews.freebsd.org/D38697