ibmvnic: device remove has higher precedence over reset

Returning -EBUSY in ibmvnic_remove() does not actually hold the
removal procedure since driver core doesn't care for the return
value (see __device_release_driver() in drivers/base/dd.c
calling dev->bus->remove()) though vio_bus_remove
(in arch/powerpc/platforms/pseries/vio.c) records the
return value and passes it on. [1]

During the device removal precedure, checking for resetting
bit is dropped so that we can continue executing all the
cleanup calls in the rest of the remove function. Otherwise,
it can cause latent memory leaks and kernel crashes.

[1] https://lore.kernel.org/linuxppc-dev/20210117101242.dpwayq6wdgfdzirl@pengutronix.de/T/#m48f5befd96bc9842ece2a3ad14f4c27747206a53Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Fixes: 7d7195a0 ("ibmvnic: Do not process device remove during device reset")
Signed-off-by: Lijun Pan <ljp@linux.ibm.com>
Link: https://lore.kernel.org/r/20210129043402.95744-1-ljp@linux.ibm.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/ibm/ibmvnic.c

@@ -5444,11 +5444,6 @@ static int ibmvnic_remove(struct vio_dev *dev)
 	unsigned long flags;
 
 	spin_lock_irqsave(&adapter->state_lock, flags);
-	if (test_bit(0, &adapter->resetting)) {
-		spin_unlock_irqrestore(&adapter->state_lock, flags);
-		return -EBUSY;
-	}
-
 	adapter->state = VNIC_REMOVING;
 	spin_unlock_irqrestore(&adapter->state_lock, flags);