Remove a log message about setting linkstate for an unknown interface.

sometimes we do want to try to set the linkstate for interfaces that are not in use by public addresses right now (but posisbly by other mechanisms) and these messages just spam the logs

S1026357

(This used to be ctdb commit f2fe0a090a9650910ebe49514b3ca01dc593bea3)

ctdb/server/ctdb_takeover.c

@@ -2633,8 +2633,6 @@ int32_t ctdb_control_set_iface_link(struct ctdb_context *ctdb,
 
 	iface = ctdb_find_iface(ctdb, info->name);
 	if (iface == NULL) {
-		DEBUG(DEBUG_ERR, (__location__ "iface[%s] is unknown\n",
-				  info->name));
 		return -1;
 	}