blocklist: Revert upstream commit ddf6d71

Upstream commit ddf6d71 ("implement BLOCKLIST_BAD_USER as a "one-count"
failure") introduced BLOCKLIST_BAD_USER with a one-count failure
mechanism. BLOCKLIST_AUTH_FAIL was implemented with a two-count failure
mechanism. Since we have been utilizing BLOCKLIST_AUTH_FAIL, the number
of failed attempts now doubles towards the maximum limit (nfails),
giving system administrators the impression that the number of failed
authentication attempts is inaccurate.

Revert this commit until a consensus has been reached. We do not want
to introduce yet another breaking change with the renaming of the
library.

Approved by: emaste (mentor)
MFC after: 2 days