libbe needs snprintf() overflow checking
libbe uses snprintf to assemble many different strings that it uses for various purposes, such as eventually executing things ala installboot and installgrub. Right now these snprintf routines are being cast to void, even though they're using a static character buffer. This means that they could end up generating an incorrect string due to input buffer overflow. Due to snprintf, this won't result in the case where internal memory is clobbered; however, it could easily lead to a confusing error being generated.