ibmvnic: init_tx_pools move loop-invariant code

In init_tx_pools() move some loop-invariant code out of the loop.

Reviewed-by: Rick Lindsley <ricklind@linux.vnet.ibm.com>
Reviewed-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>
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 97041b3..bb9b8ae 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -843,11 +843,10 @@ static int init_tx_pools(struct net_device *netdev)
 	 * allocation, release_tx_pools() will know how many to look for.
 	 */
 	adapter->num_active_tx_pools = num_pools;
+	buff_size = adapter->req_mtu + VLAN_HLEN;
+	buff_size = ALIGN(buff_size, L1_CACHE_BYTES);
 
 	for (i = 0; i < num_pools; i++) {
-		buff_size = adapter->req_mtu + VLAN_HLEN;
-		buff_size = ALIGN(buff_size, L1_CACHE_BYTES);
-
 		dev_dbg(dev, "Init tx pool %d [%llu, %llu]\n",
 			i, adapter->req_tx_entries_per_subcrq, buff_size);