libcompat: do not use _snprintf even if available
libcompat: do not use _snprintf even if available

After going back and forth on this one, it seems simpler to
use libcompat's snprintf, even if _snprintf is available.

There were issues on MSVC using _snprintf.

git-svn-id: ae38cf1093b87151f738d2b2220cac7742ad2e55@995 64e312b2-a51f-0410-8e61-82d0ca0eb02a

lubosz/check,lubosz/check,lubosz/check,lubosz/check