Change flag and lvl check from bitwise & to &&

I was thinking about submitting an issue but thought it made more sense to have the code at hand. `logFlag` and `logLevel` are both type `int` but we're doing a bitwise comparison to determine whether or not a given logger should log a message. That means for many values of `logFlag` we simply aren't going to log, no matter what the logLevel is. Maybe I'm misunderstanding the reason for the flag?