net: sfc: Use pci_clear_master() to disable bus mastering

pci_disable_device() disables many features, like MSI-X, which we
never reenable in efx_reset().  Further, calls to pci_enable_device()
and pci_disable_device() must be matched since the nesting count was
introduced, so switch to using pci_clear_master() instead.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/net/sfc/falcon.c

@@ -1403,9 +1403,9 @@ static irqreturn_t falcon_fatal_interrupt(struct efx_nic *efx)
 	}
 
 	/* Disable both devices */
-	pci_disable_device(efx->pci_dev);
+	pci_clear_master(efx->pci_dev);
 	if (FALCON_IS_DUAL_FUNC(efx))
-		pci_disable_device(nic_data->pci_dev2);
+		pci_clear_master(nic_data->pci_dev2);
 	falcon_disable_interrupts(efx);
 
 	if (++n_int_errors < FALCON_MAX_INT_ERRORS) {