Regression: SUNRPC: Use poll() to fix up the socket requeue races

[Jon Hunter]

Hi Trond,

Starting in next-20190222 I have observed a regression with NFS causing
some of our boards to fail to boot. Bisect points to your commit ...

commit 0ffe86f48026b7f34db22d1004bc9992f0db8b33
Author: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Date:   Wed Jan 30 14:51:26 2019 -0500

    SUNRPC: Use poll() to fix up the socket requeue races


After reverting this on top of -next I no longer see the problem. I have
not had chance to look any closer, but wanted to see if you had any
ideas what might be the problem.

Cheers
Jon