ng_iface: don't recursively enter epoch in the rcvdata method

Reviewed by:		p.mousavizadeh_protonmail.com, zlei
Differential Revision:	https://reviews.freebsd.org/D54241

sys/netgraph/ng_iface.c

@@ -680,7 +680,6 @@ ng_iface_rcvdata(hook_p hook, item_p item)
 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
 	struct ifnet *const ifp = priv->ifp;
-	struct epoch_tracker et;
 	struct mbuf *m;
 	int isr;
 
@@ -723,9 +722,7 @@ ng_iface_rcvdata(hook_p hook, item_p item)
 	random_harvest_queue(m, sizeof(*m), RANDOM_NET_NG);
 	M_SETFIB(m, ifp->if_fib);
 	CURVNET_SET(ifp->if_vnet);
-	NET_EPOCH_ENTER(et);
 	netisr_dispatch(isr, m);
-	NET_EPOCH_EXIT(et);
 	CURVNET_RESTORE();
 	return (0);
 }