sm(4) is too verbose

[David Gwynne]

sm(4) doenst have to bpfdetach cos if_detach will do it for it.

also, useless comments are useless.

ok?

Index: dev/ic/smc91cxx.c
===================================================================
RCS file: /cvs/src/sys/dev/ic/smc91cxx.c,v
retrieving revision 1.35
diff -u -p -r1.35 smc91cxx.c
--- dev/ic/smc91cxx.c   22 Jul 2014 13:12:12 -0000      1.35
+++ dev/ic/smc91cxx.c   23 Sep 2014 01:20:29 -0000
@@ -697,7 +697,6 @@ smc91cxx_start(ifp)
        ifp->if_timer = 5;
 
 #if NBPFILTER > 0
-       /* Hand off a copy to the bpf. */
        if (ifp->if_bpf)
                bpf_mtap(ifp->if_bpf, top, BPF_DIRECTION_OUT);
 #endif
@@ -997,10 +996,6 @@ smc91cxx_read(sc)
        ifp->if_ipackets++;
 
 #if NBPFILTER > 0
-       /*
-        * Hand the packet off to bpf listeners.  If there's a bpf listener,
-        * we need to check if the packet is ours.
-        */
        if (ifp->if_bpf)
                bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_IN);
 #endif
@@ -1239,9 +1234,6 @@ smc91cxx_detach(self, flags)
        /* Delete all media. */
        ifmedia_delete_instance(&sc->sc_mii.mii_media, IFM_INST_ANY);
 
-#if NBPFILTER > 0
-       bpfdetach(ifp);
-#endif
        ether_ifdetach(ifp);
        if_detach(ifp);