hostip: comment fixed to state current situation

 * 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.

 */