Use a more robust idiom When converting sprintf() to snprintf()

Use a more robust idiom When converting sprintf() to snprintf()

don't use the idiom

char foo[BUFSIZ];
snprintf(foo, BUFSIZ, ....);

but

char foo[BUFSIZ];
snprintf(foo, sizeo foo, ....);

because this will automatically catch situations where the size of foo
is later changed, e.g. like  foo[BUFSIZ + 8];

Fix another use of sprintf.