This reverts commit 59a252ff.

This helps in an entirely cached workload but not necessarily in
workloads that require waiting on disk.

Conflicts:

	include/linux/sunrpc/svc.h
	net/sunrpc/svc_xprt.c
Reported-by: NSimon Kirby <sim@hostway.ca>
Tested-by: NJesper Krogh <jesper@krogh.cc>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>