ibmvnic: Check CRQ command return codes

Check whether CRQ command is successful before awaiting a response
from the management partition. If the command was not successful, the
driver may hang waiting for a response that will never come.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>