config.c: fix storage size

The following warning is emitted by gcc 7.0 pre:

>   CC       config.lo
> config.c: In function ‘vps_save_config’:
> config.c:422:30: warning: ‘%g’ directive output may be truncated writing between 1 and 13 bytes into a region of size 12 [-Wformat-truncation=]
>   snprintf(buf, sizeof(buf), "%g", val);
>                               ^~
> config.c:422:2: note: ‘snprintf’ output between 2 and 14 bytes into a destination of size 12
>   snprintf(buf, sizeof(buf), "%g", val);

Fix it.

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
1 file changed