dsdb: Clarify that most errors in make_error_and_update_badPwdCount() are not returned

dsdb: Clarify that most errors in make_error_and_update_badPwdCount() are not returned

This is mainly just to be clear, and was done while failing to work around compiler
warnings.

For the curious it was gcc version 4.8.5 20150623 (Red Hat 4.8.5-44) (CentOS 7)
build with -O3, which gave with other, later patches:

../../source4/dsdb/samdb/ldb_modules/password_hash.c: In function ‘check_password_restrictions_and_log’:
../../source4/dsdb/samdb/ldb_modules/password_hash.c:3231:5: error: assuming signed overflow does not occur when simplifying conditional to constant [-Werror=strict-overflow]
  if (ret == LDB_SUCCESS) {
     ^

Regardless, we make it clear that all values assigned to "ret" are
local small constants.

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Joseph Sutton <josephsutton@catalyst.net.nz>