The buffer address is always overwritten in the extended descriptor f…

…ormat,

we have to refresh it ... always.  This fixes problems reported in NetMap
with em(4) devices after conversion to extended descriptor format in
svn r293331.

Submitted by:	luigi@
Reported by:	franco@opnsense.org
MFC after:	2 days

sys/dev/netmap/if_em_netmap.h

@@ -277,9 +277,9 @@ em_netmap_rxsync(struct netmap_kring *kring, int flags)
 			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
 				goto ring_reset;
 
+			curr->read.buffer_addr = htole64(paddr);
 			if (slot->flags & NS_BUF_CHANGED) {
 				/* buffer has changed, reload map */
-				curr->read.buffer_addr = htole64(paddr);
 				netmap_reload_map(na, rxr->rxtag, rxbuf->map, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}