Revert "ibmvnic: remove duplicate napi_schedule call in open function"

This reverts commit 7c451f3e.

When a vnic interface is taken down and then up, connectivity is not
restored. We bisected it to this commit. Reverting this commit until
we can fully investigate the issue/benefit of the change.

Fixes: 7c451f3e ("ibmvnic: remove duplicate napi_schedule call in open function")
Reported-by: Cristobal Forno <cforno12@linux.ibm.com>
Reported-by: Abdul Haleem <abdhalee@in.ibm.com>
Signed-off-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>