jail: Fix redoing ip restricting

[zlei]

Summary

prison_ip_restrict() is called in loop FOREACH_PRISON_DESCENDANT_LOCKED. While under low memory, it is still possible that subsequent round prison_ip_restrict() succeed and redo_ip[4,6] flip over from true to false, thus leave some prisons's IPv[4,6] addresses unrestricted.

Fixes: 8bce8d28abe6 jail: Avoid multipurpose return value of function prison_ip_restrict()

[jamie]

This makes perfect sense to me. The original version only set redo_ip[46] provisionally , and I missed that the patch changed that.