Revert "dns cache per interface iteration 2"

This reverts commit f1464ff95670e6dcc0e12bf9fbbeb4c0346434c9

Change-Id: I3496b9a8cb54614fe3eea016d1391c8a89f3db38
diff --git a/libc/private/resolv_private.h b/libc/private/resolv_private.h
index 1c3c1a2..0f3c6c0 100644
--- a/libc/private/resolv_private.h
+++ b/libc/private/resolv_private.h
@@ -56,7 +56,6 @@
 
 #include <resolv.h>
 #include "resolv_static.h"
-#include <net/if.h>
 
 /*
  * Revision information.  This is the release date in YYYYMMDD format.
@@ -140,7 +139,6 @@
 struct __res_state_ext;
 
 struct __res_state {
-	char	iface[IF_NAMESIZE+1];
 	int	retrans;	 	/* retransmission time interval */
 	int	retry;			/* number of times to retransmit */
 #ifdef sun
@@ -493,7 +491,7 @@
 int		res_getservers(res_state,
 				    union res_sockaddr_union *, int);
 
-void res_setiface();
+int res_get_dns_changed();
 u_int  res_randomid(void);
 
 __END_DECLS