Fix test-badsetting when not all hashes are enabled.
Fix test-badsetting when not all hashes are enabled.

It turns out I was wrong to think that we could safely leave the
subtests for excluded hashes enabled, because you get a slightly
different error in some cases (EINVAL instead of ERANGE).  Instead,
for excluded hashes, check that a *correct* gensalt invocation will
still fail.

besser82/libxcrypt,besser82/libxcrypt,besser82/libxcrypt,besser82/libxcrypt