ath9k: Remove bf_dmacontext.

The bf_dmacontext seems to be totally useless and duplicated
by bf_buf_addr.  Remove it entirely, use bf_buf_addr in its
place.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/recv.c

@@ -363,7 +363,6 @@ int ath_rx_init(struct ath_softc *sc, int nbufs)
 				error = -ENOMEM;
 				goto err;
 			}
-			bf->bf_dmacontext = bf->bf_buf_addr;
 		}
 		sc->rx.rxlink = NULL;
 	}
@@ -1739,7 +1738,6 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 			ath_rx_send_to_mac80211(hw, sc, skb, rxs);
 			break;
 		}
-		bf->bf_dmacontext = bf->bf_buf_addr;
 
 		/*
 		 * change the default rx antenna if rx diversity chooses the