hostip: comment fixed to state current situation

lib/hostip.c

@@ -110,11 +110,13 @@
  * hostip.c   - method-independent resolver functions and utility functions
  * hostasyn.c - functions for asynchronous name resolves
  * hostsyn.c  - functions for synchronous name resolves
- * hostares.c - functions for ares-using name resolves
- * hostthre.c - functions for threaded name resolves
  * hostip4.c  - ipv4-specific functions
  * hostip6.c  - ipv6-specific functions
  *
+ * The two asynchronous name resolver backends are implemented in:
+ * asyn-ares.c   - functions for ares-using name resolves
+ * asyn-thread.c - functions for threaded name resolves
+
  * The hostip.h is the united header file for all this. It defines the
  * CURLRES_* defines based on the config*.h and setup.h defines.
  */