To avoid the following failure when trying to load the rdma_rxe module
while IPv6 is disabled, add a check for EAFNOSUPPORT and ignore the
failure, also delete the needless debug print from rxe_setup_udp_tunnel().

$ modprobe rdma_rxe
modprobe: ERROR: could not insert 'rdma_rxe': Operation not permitted

Fixes: dfdd6158 ("IB/rxe: Fix kernel panic in udp_setup_tunnel")
Link: https://lore.kernel.org/r/20210603090112.36341-1-kamalheib1@gmail.comReported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Kamal Heib <kamalheib1@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>