brcmfmac: sdio unload fix.

on sdio remove the bus_if should be configured for close, so
new data from higher layers will be blocked. Also the access
to bus_if in the watchdog should be checked for null pointer
access on sdio remove.
Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/brcm80211/brcmfmac/bcmsdh.c

@@ -535,6 +535,8 @@ EXPORT_SYMBOL(brcmf_sdio_probe);
 
 int brcmf_sdio_remove(struct brcmf_sdio_dev *sdiodev)
 {
+	sdiodev->bus_if->state = BRCMF_BUS_DOWN;
+
 	if (sdiodev->bus) {
 		brcmf_sdbrcm_disconnect(sdiodev->bus);
 		sdiodev->bus = NULL;

drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c

@@ -3576,7 +3576,7 @@ static bool brcmf_sdbrcm_bus_watchdog(struct brcmf_sdio *bus)
 	}
 #ifdef DEBUG
 	/* Poll for console output periodically */
-	if (bus_if->state == BRCMF_BUS_DATA &&
+	if (bus_if && bus_if->state == BRCMF_BUS_DATA &&
 	    bus->console_interval != 0) {
 		bus->console.count += BRCMF_WD_POLL_MS;
 		if (bus->console.count >= bus->console_interval) {