brcmfmac: stop releasing sdio host in irq handler

brcmf_sdbrcm_isr doesn't access to the dongle through SDIO bus.
Stop releasing and claiming host in irq handler to eliminate
any potential risk.
Reviewed-by: NPieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: NArend van Spriel <arend@broadcom.com>
Signed-off-by: NFranky Lin <frankyl@broadcom.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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

@@ -45,11 +45,7 @@ static void brcmf_sdioh_irqhandler(struct sdio_func *func)
 
 	brcmf_dbg(TRACE, "***IRQHandler\n");
 
-	sdio_release_host(func);
-
 	brcmf_sdbrcm_isr(sdiodev->bus);
-
-	sdio_claim_host(func);
 }
 
 /* dummy handler for SDIO function 2 interrupt */