vxge: check for card status before continuing in device close

- Fixed the crash in rmmod after vpath open failed when trying to change mtu.
We should check for card status before continuing in device close.

Signed-off-by: Sreenivasa Honnur <sreenivasa.honnur@neterion.com>
Signed-off-by: Ramkrishna Vepa <ram.vepa@neterion.com>
Signed-off-by: David S. Miller <davem@davemloft.net>