Fix crash in rk_freeifaddrs due to freeing an invalid pointer

Crash occurs on Linux systems that support AF_NETLINK but do not have
getifaddrs() in libc (eg. SuSE 8.1).

Signed-off-by: Love Hornquist Astrand <lha@h5l.org>

lib/roken/getifaddrs.c

@@ -853,6 +853,13 @@ rk_getifaddrs(struct ifaddrs **ifap)
   return 0;
 }
 
+void ROKEN_LIB_FUNCTION
+rk_freeifaddrs(struct ifaddrs *ifp)
+{
+    /* AF_NETLINK method uses a single allocation for all interfaces */
+    free(ifp);
+}
+
 #else /* !AF_NETLINK */
 
 /*
@@ -1175,8 +1182,6 @@ rk_getifaddrs(struct ifaddrs **ifap)
     return ret;
 }
 
-#endif /* !AF_NETLINK */
-
 void ROKEN_LIB_FUNCTION
 rk_freeifaddrs(struct ifaddrs *ifp)
 {
@@ -1198,6 +1203,8 @@ rk_freeifaddrs(struct ifaddrs *ifp)
     }
 }
 
+#endif /* !AF_NETLINK */
+
 #ifdef TEST
 
 void