drivers: infiniband: Fix compiler warning

This patch fixes the following compiler warning of uninitialized variable

drivers/infiniband/hw/mlx4/qp.c: In function ‘mlx4_ib_post_send’:
drivers/infiniband/hw/mlx4/qp.c:1862:62: warning: ‘vlan’ may be used uninitialized in this function [-Wmaybe-uninitialized] drivers/infiniband/hw/mlx4/qp.c:1752:6: note: ‘vlan’ was declared here

---
 drivers/infiniband/hw/mlx4/qp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 19e0637..37829b6 100644
@@ -1749,7 +1749,7 @@ static int build_mlx_header(struct mlx4_ib_sqp *sqp, struct ib_send_wr *wr,
        int is_eth;
        int is_vlan = 0;
        int is_grh;
-       u16 vlan;
+       u16 vlan = 0;
        int err = 0;
 
        send_size = 0;

1.8.1