ath9k: use new FIF_PSPOLL configure filter

We used to set pspoll filter on ath9k on AP mode but
we no longer need this mode specific check as mac80211
now does the check for us and informs us when we should
enable pspoll through FIF_PSPOLL.

Cc: Igor Perminov <igor.perminov@inbox.ru>
Cc: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -448,8 +448,7 @@ u32 ath_calcrxfilter(struct ath_softc *sc)
 	else
 		rfilt |= ATH9K_RX_FILTER_BEACON;
 
-	/* If in HOSTAP mode, want to enable reception of PSPOLL frames */
-	if (sc->sc_ah->opmode == NL80211_IFTYPE_AP)
+	if (sc->rx.rxfilter & FIF_PSPOLL)
 		rfilt |= ATH9K_RX_FILTER_PSPOLL;
 
 	if (sc->sec_wiphy) {