VFIO: platform: reset: fix a warning message condition

This loop ends with count set to -1 and not zero so the warning message
isn't printed when it should be.  I've fixed this by change the postop
to a preop.

Fixes: 0990822c9866 ('VFIO: platform: reset: AMD xgbe reset module')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/platform/reset/vfio_platform_amdxgbe.c

@@ -110,7 +110,7 @@ int vfio_platform_amdxgbe_reset(struct vfio_platform_device *vdev)
 	usleep_range(10, 15);
 
 	count = 2000;
-	while (count-- && (ioread32(xgmac_regs->ioaddr + DMA_MR) & 1))
+	while (--count && (ioread32(xgmac_regs->ioaddr + DMA_MR) & 1))
 		usleep_range(500, 600);
 
 	if (!count)