ath9k: reset after PCI FATAL/PERR interrupts

ath9k_hw_getisr() doesn't appear to set anything in the status mask for
PCI FATAL or PERR interrupts (AR_INTR_SYNC_HOST1_FATAL/PERR), which
the open-source HAL seems to do.  This means that the card isn't reset
after these interrupts.

This patch seems to fix a problem where the wireless drops out with an
"ath9k: received PCI FATAL interrupt" in dmesg after some time; the
hardware is an AR5416 in an ASUS WL-500W running 2.6.28.7 (OpenWRT) and
compat-wireless 2009-03-31.
Signed-off-by: Steven Luo <steven@steven676.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -2976,6 +2976,7 @@ bool ath9k_hw_getisr(struct ath_hw *ah, enum ath9k_int *masked)
 				DPRINTF(ah->ah_sc, ATH_DBG_ANY,
 					"received PCI PERR interrupt\n");
 			}
+			*masked |= ATH9K_INT_FATAL;
 		}
 		if (sync_cause & AR_INTR_SYNC_RADM_CPL_TIMEOUT) {
 			DPRINTF(ah->ah_sc, ATH_DBG_INTERRUPT,