i40e/i40evf: set AQ count after memory allocation

The standard way to check if the AQ is enabled is to look at the
count field. So we should only set this field after we have
successfully allocated memory. To do otherwise is to incite
panic among the populace.

Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>