RX: Force sane timeout values

RX: Force sane timeout values

Currently we do not check the specified timeout values when someone
changes a connection's dead, idle, or hard dead time. However, if the
conn's dead time is larger than the other two times, a loss of network
activity will result in one of the other timeouts getting triggered
first.

To prevent this and possibly other problems from happening, force a
connection's timeouts to always obey the relationship
secondsUntilDead <= idleDeadTime <= hardDeadTime, by checking these
values whenever they are changed.

Change-Id: Ib9a0c65d91b4dc61c8d00381c8266b88b1d89b81
Reviewed-on: http://gerrit.openafs.org/2947
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>
(cherry picked from commit 7d6080a841ff8c91052fa708d5be3b582f8a971d)
Reviewed-on: http://gerrit.openafs.org/3065
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>