Method to abort the authentication process (phase 2).
This method is called if the LoginContext's overall authentication failed. (the relevant REQUIRED, REQUISITE, SUFFICIENT and OPTIONAL LoginModules did not succeed).
If this LoginModule's own authentication attempt succeeded (checked by retrieving the private state saved by the {@code login} method), then this method cleans up any statethat was originally saved.
@exception LoginException if the abort fails
@return true if this method succeeded, or false if this{@code LoginModule} should be ignored.