ibmvnic: Correct 'unused variable' warning in build.

Commit a248878d ("ibmvnic: Check for transport event on driver resume")
removed the loop to kick irqs on driver resume but didn't remove the now
unused loop variable 'i'.

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