Kill redundant checks around routerset_contains_*()

All of the routerset_contains*() functions return 0 if their
routerset_t argument is NULL.  Therefore, there's no point in
doing "if (ExcludeNodes && routerset_contains*(ExcludeNodes...))",
for example.

This patch fixes every instance of
         if (X && routerstatus_contains*(X,...))

Note that there are other patterns that _aren't_ redundant.  For
example, we *don't* want to change:
        if (EntryNodes && !routerstatus_contains(EntryNodes,...))

Fixes #2797.  No bug here; just needless code.

0 files changed, 0 insertions, 0 deletions