be2iscsi: Fix memory leak in mgmt_set_ip()

The if_info pointer is not released by the mgmt_set_ip() function

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>