LU-12780 lustre: remove SVC_EVENT flag

LU-12780 lustre: remove SVC_EVENT flag

This flag is never set or tested, so remove it and the
function for testing it.

Test-Parameters:trivial

Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: Ie9fc586ecd26ffce16026d53eac998e3c046d270
Reviewed-on: https://review.whamcloud.com/36257
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Shaun Tancheff <stancheff@cray.com>
Reviewed-by: Petros Koutoupis <pkoutoupis@cray.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>