overflow checked snprintf(). for res_debug.c and res_query.c, convert
from sprintf() to snprintf().
tested scp and rcp fail properly with too-long paths.
tested getaddrinfo fails as expected for too-long domains.
tested dig and ping for similar (res_debug.c/res_query.c).
created a temporary fs with quotas to test edquota with a long EDITOR.
did not test ypserv directly, but it's the same pattern.
avoids GCC 12 snprintf() warnings, and reduces total code size.