[Dovecot] typo in failures.c

[Kenneth Porter]

--On Saturday, June 07, 2008 5:11 AM +0300 Timo Sirainen <tss at iki.fi> wrote:

> I wish gcc warned about bad enum usages, it would have caught this.

Wow, that surprised me that it lacked that, as I'm so used to it on 
Windows. But I mostly code in C++ there, so perhaps the conversion in C is 
legal?

<http://gcc.gnu.org/ml/gcc/2004-07/msg00375.html>

Except that conversion from one enum type to another looks like it should 
be illegal based on that message.