ssa.c: Minor reorganization of ssa_svc_listen

Defer setting of fd input events in pollfd struct to POLLIN to
when fd is "claimed" (at listen rather than init_fds).
This is in preparation for adding (ACM) client connection support.

Also, move src_addr initialization closer to where needed in code flow
(immediately prior to rbind).

Signed-off-by: Hal Rosenstock <hal@mellanox.com>
Acked-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
ssa.c: Cosmetic format change to fix indentation

Signed-off-by: Hal Rosenstock <hal@mellanox.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>