SUNRPC: Avoid RPC delays when exiting suspend

Jon Hunter: "I have been tracking down another suspend/NFS related
issue where again I am seeing random delays exiting suspend. The delays
can be up to a couple minutes in the worst case and this is causing a
suspend test we have to fail."

Change the use of a deferrable work to a standard delayed one.

Reported-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Fixes: 7e0a0e38

 ("SUNRPC: Replace the queue timer with a delayed work function")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>