RDMA/efa: Free IRQ vectors on error flow

Make sure to free the IRQ vectors in case the allocation doesn't return
the expected number of IRQs.

Fixes: b7f5e880

 ("RDMA/efa: Add the efa module")
Link: https://lore.kernel.org/r/20210811151131.39138-2-galpress@amazon.com
Reviewed-by: Firas JahJah <firasj@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>