Cleanup: Delete dead code.

Bug: 15413389
Change-Id: I315468832ef18ffc84174e54774ab63b86d284dc
diff --git a/libc/dns/include/resolv_netid.h b/libc/dns/include/resolv_netid.h
index d4668c3..f1b8892 100644
--- a/libc/dns/include/resolv_netid.h
+++ b/libc/dns/include/resolv_netid.h
@@ -36,7 +36,7 @@
 #include <netinet/in.h>
 
 /*
- * Passing NETID_UNSET as the netId causes system/netd/DnsProxyListener.cpp to
+ * Passing NETID_UNSET as the netId causes system/netd/server/DnsProxyListener.cpp to
  * fill in the appropriate default netId for the query.
  */
 #define NETID_UNSET 0u
@@ -61,9 +61,6 @@
 extern void _resolv_set_nameservers_for_net(unsigned netid,
     const char** servers, int numservers, const char *domains) __used_in_netd;
 
-/* flush the cache associated with a certain network */
-extern void _resolv_flush_cache_for_net(unsigned netid) __used_in_netd;
-
 /* delete the cache associated with a certain network */
 extern void _resolv_delete_cache_for_net(unsigned netid) __used_in_netd;