Remove __LIBC_HIDDEN__

Now that we're hiding all symbols, there's no point in hand-picking
which ones to hide.

Test: atest netd_integration_test
Change-Id: Id88f10cb4c8e25635b6f4c94118a6b3a27b14cb5
diff --git a/resolv/resolv_cache.h b/resolv/resolv_cache.h
index 24fbf9b..cc7b5b7 100644
--- a/resolv/resolv_cache.h
+++ b/resolv/resolv_cache.h
@@ -29,15 +29,13 @@
 #define _RESOLV_CACHE_H_
 
 #include <stddef.h>
-#include <sys/cdefs.h>
 
 struct __res_state;
 
 /* sets the name server addresses to the provided res_state structure. The
  * name servers are retrieved from the cache which is associated
  * with the network to which the res_state structure is associated */
-__LIBC_HIDDEN__
-extern void _resolv_populate_res_for_net(struct __res_state* statp);
+void _resolv_populate_res_for_net(struct __res_state* statp);
 
 typedef enum {
     RESOLV_CACHE_UNSUPPORTED, /* the cache can't handle that kind of queries */
@@ -46,19 +44,17 @@
     RESOLV_CACHE_FOUND        /* the cache found the answer */
 } ResolvCacheStatus;
 
-__LIBC_HIDDEN__
-extern ResolvCacheStatus _resolv_cache_lookup(unsigned netid, const void* query, int querylen,
-                                              void* answer, int answersize, int* answerlen);
+ResolvCacheStatus _resolv_cache_lookup(unsigned netid, const void* query, int querylen,
+                                       void* answer, int answersize,
+                                       int* answerlen);
 
 /* add a (query,answer) to the cache, only call if _resolv_cache_lookup
  * did return RESOLV_CACHE_NOTFOUND
  */
-__LIBC_HIDDEN__
-extern void _resolv_cache_add(unsigned netid, const void* query, int querylen, const void* answer,
-                              int answerlen);
+void _resolv_cache_add(unsigned netid, const void* query, int querylen, const void* answer,
+                       int answerlen);
 
 /* Notify the cache a request failed */
-__LIBC_HIDDEN__
-extern void _resolv_cache_query_failed(unsigned netid, const void* query, int querylen);
+void _resolv_cache_query_failed(unsigned netid, const void* query, int querylen);
 
 #endif /* _RESOLV_CACHE_H_ */