[linux-3.13.y.z] Fixes for kernel nfs server

[Stefan Bader]

We have a bug report about the NFS kernel server getting into
a tight loop under certain circumstances. Looking at the debug
data it could be seen that the RPC service seemed to be too
quickly doing retries of some connects.

The code causing this seemed to be introduced in 3.13 by

  561ec1603171 SUNRPC: call_connect_status should recheck bind..

which has two follow up patches in 3.15 referring to it:

  1fa3e2e SUNRPC: Ensure call_connect_status() deals correctly
          with SOFTCONN tasks
  485f225 SUNRPC: Ensure that call_connect times out correctly

Both patches have been applied to 3.14.4 already. But the second
(485f225) required some light adjustment to apply. A test kernel
with both has been tested and looks to be stable.

Proposing the following patches to be included in the 3.13 longterm
tree (and pulled into Trusty).

-Stefan