RDMA/iw_cgxb4: Fix an error handling path in 'c4iw_connect()'

We should jump to fail3 in order to undo the 'xa_insert_irq()' call.

Link: https://lore.kernel.org/r/20190923190746.10964-1-christophe.jaillet@wanadoo.fr


Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>