rdma: do not mix newline and json object

rdma: do not mix newline and json object

Mixing the semantics of ending lines with the json object
leads to several bugs where json object is closed twice, etc.
Replace by breaking the meaning of newline() function into
two parts.

Now, lots of functions were taking the rdma data structure as
argument but never using it.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>