IfAPI: fix LINT-NOIP build

Also, reimplement the wrappers with __strong_reference macro.

Fixes:		7b3094df479f
Reported by:	zlei
Sponsored by:	Juniper Networks, Inc.
Reviewed by:	zlei, jhibbits
Differential Revision:	https://reviews.freebsd.org/D52362

sys/net/bpf.c

@@ -3223,6 +3223,8 @@ bpf_validate(const struct bpf_insn *f, int len)
 
 #endif /* !DEV_BPF && !NETGRAPH_BPF */
 
+__strong_reference(bpf_mtap_if, if_bpfmtap);
+
 #ifdef DDB
 static void
 bpf_show_bpf_if(struct bpf_if *bpf_if)

sys/net/if.c

@@ -4866,18 +4866,6 @@ if_gethandle(u_char type)
 	return (if_alloc(type));
 }
 
-void
-if_bpfmtap(if_t ifp, struct mbuf *m)
-{
-       bpf_mtap_if(ifp, m);
-}
-
-void
-if_etherbpfmtap(if_t ifp, struct mbuf *m)
-{
-       ether_bpf_mtap_if(ifp, m);
-}
-
 void
 if_vlancap(if_t ifp)
 {

sys/net/if_ethersubr.c

@@ -1551,5 +1551,7 @@ ether_gen_addr(struct ifnet *ifp, struct ether_addr *hwaddr)
 	ether_gen_addr_byname(if_name(ifp), hwaddr);
 }
 
+__strong_reference(ether_bpf_mtap_if, if_etherbpfmtap);
+
 DECLARE_MODULE(ether, ether_mod, SI_SUB_INIT_IF, SI_ORDER_ANY);
 MODULE_VERSION(ether, 1);