inet: gethostid: only accept v4 addresses

getaddrinfo() returns addresses from, at least, ip(7) and ipv6(7),
but _addr() always uses sin_addr from struct sockaddr_in;
we're saved from wild unsoundness (or incompatibility)
by virtue of struct sockaddr_in6 having an always-0 u32 sin6_flowinfo
at the same offset, so we end up returning 0 anyway,
but in a round-about and definitely unintended way

Instead, limit the request to AF_INET, and fall through to the end
early, returning the default id=0

Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>

libc/inet/hostid.c

@@ -61,8 +61,7 @@ long int gethostid(void)
 	 *						Mitch
 	 */
 	if (gethostname(host, HOST_NAME_MAX) >= 0 && *host) {
-		struct addrinfo hints, *results, *addr;
-		memset(&hints, 0, sizeof(struct addrinfo));
+		struct addrinfo hints = {.ai_family = AF_INET}, *results, *addr;
 		if (!getaddrinfo(host, NULL, &hints, &results)) {
 			for (addr = results; addr; addr = results->ai_next) {
 				/* Just so it doesn't look exactly like the