staging: lustre: use wait_event_idle_timeout() where appropriate.

When the lwi arg has a timeout, but no timeout
callback function, l_wait_event() acts much the same as
wait_event_idle_timeout() - the wait is not interruptible and
simply waits for the event or the timeouts.

The most noticable difference is that the return value is
-ETIMEDOUT or 0, rather than 0 or non-zero.

Another difference is that if the timeout is zero, l_wait_event()
will not time out at all.  In the one case where that is possible
we need to conditionally use wait_event_idle().

So replace all such calls with wait_event_idle_timeout(), being
careful of the return value.

In one case, there is no event expected, only the timeout
is needed.  So use schedule_timeout_uninterruptible().

Note that the presence or absence of LWI_ON_SIGNAL_NOOP
has no effect in these cases.  It only has effect if the timeout
callback is non-NULL, or the timeout is zero, or
LWI_TIMEOUT_INTR_ALL() is used.

Reviewed-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: Patrick Farrell <paf@cray.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>