bnxt_re: changing the ip address shouldn't affect new connections
While adding a new gid, the driver currently does not return the context
back to the stack. A subsequent del_gid() (e.g, when ip address is changed)
doesn't find the right context in the driver and it ends up dropping that
request. This results in the HW caching a stale gid entry and traffic fails
because of that. Fix by returning the proper context in bnxt_re_add_gid().