ibmvnic: Remove inflight list

The inflight list used to track memory that is allocated for crq that are
inflight is not needed. The one piece of the inflight list that does need
to be cleaned at module exit is the error buffer list which is already
attached to the adapter struct.

This patch removes the inflight list and moves checking the error buffer
list to ibmvnic_remove.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>