It's possible that while we are waiting for the spinlock, another
entity (that owns the spinlock) has shut down the admin queue.
If we then attempt to use the queue, we will panic.

Add a check for this condition on the receive side. This matches
an existing check on the send queue side.
Signed-off-by: NMitch Williams <mitch.a.williams@intel.com>
Acked-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>