Check the device connected state prior to executing device shutdown
operations or writing MSI messages so that tear down on disconnected
devices completes quicker.
Tested-by: Krishna Dhulipala <krishnad@fb.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Wei Zhang <wzhang@fb.com>