LU-6142 lustre: remove imp_no_timeout field

LU-6142 lustre: remove imp_no_timeout field

This field is never set and never used.  Remove it.

Test-Parameters: trivial
Signed-off-by: Mr NeilBrown <neilb@suse.com>
Change-Id: I1dddbe620405b49e90530adcb9a7dec7f9ece64f
Reviewed-on: https://review.whamcloud.com/35877
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Arshad Hussain <arshad.super@gmail.com>