iiod: dns-sd: Fix invalid check of hostname vs. "none" string

By doing: strncmp(host, "none", sizeof("none") - 1)

We actually only check that the first 4 characters are "none"; as a
result, a "none_foobar.local" hostname would match as well.

The solution is to match the ending \0 as well:
strncmp(host, "none", sizeof("none"))

which can be simplified to just strcmp(host, "none")

Signed-off-by: Paul Cercueil <[email protected]>

iiod/dns-sd.c

@@ -256,7 +256,7 @@ static void start_avahi_thd(struct thread_pool *pool, void *d)
 	while(true) {
 		ret = gethostname(host, sizeof(host));
 		IIO_ERROR("host %s\n", host);
-		if (ret || !strncmp(host, "none", sizeof("none") - 1))
+		if (ret || !strcmp(host, "none"))
 			goto again;
 
 		iio_snprintf(label, sizeof(label), "%s%s", IIOD_ON, host);