ibmvnic: fix block comments

Fix the following checkpatch warning:
WARNING: networking block comments don't use an empty /* line, use /* Comment...

Signed-off-by: Lijun Pan <lijunp213@gmail.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>