LU-10467 lustre: use l_wait_event_abortable where appropriate.

LU-10467 lustre: use l_wait_event_abortable where appropriate.

If the lwi passed to l_wait_event() was created with

    lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);

the effect is to wait with no timeout and blocking any
non-fatal signals.
For this, we now have l_wait_event_abortable(), or for one
case l_wait_event_abortable_exclusive();
So use those.

l_wait_event_abortable() will return -ERESTARTSYS if a signal was
received, while l_wait_event() returens -EINTR.  We need to be
careful to handle this difference.

Signed-off-by: Mr NeilBrown <neilb@suse.com>
Change-Id: Iadf0fab92fcfd46802766198dcbe6b6b349214fa
Reviewed-on: https://review.whamcloud.com/35975
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Petros Koutoupis <petros.koutoupis@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>