Email rehash issue due to D7.35 API change breaks email validation

Drupal 7 core security update 7.35 introduced a change to the password rehashing adds an extra uid argument to the function user_pass_rehash which is used by logintoboggan_eml_rehash and generates a different password hash to what Core now produces. This results in a hashing failure and results in the message

confirmation link has expired

when logintobboggan is used to handle email validation for the purpose of removing a temporary role and granting a more privilaged role.

The end result is that users cannot confirm their email address and are unable to promote their user accounts to a more functional role.

I've attached a patch which fixes this issue.