Make kernel messages wait sensitive to force_prompt

Closes: #147 Only force a prompt if force_prompt is
already set. Declare the use of force_prompt in debug
logs.

Signed-off-by: Neil Williams <neil.williams@linaro.org>
13 jobs for forcewait in 8 minutes and 8 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #25908
amd64
dispatcher-debian-10

00:02:15

passed #25906
amd64
dispatcher-debian-9

00:02:34

passed #25909
amd64
server-debian-10

00:01:46

passed #25907
amd64
server-debian-9

00:02:14

 
  Analyze
passed #25910
amd64
black

00:00:24

passed #25912
amd64
code_quality

00:00:19

passed #25911
amd64
codestyle

00:00:31

passed #25913
dind amd64 allowed to fail
sast

00:01:47

 
  Build
passed #25916
amd64
amd64/pkg-debian-10

00:01:23

passed #25915
amd64
amd64/pkg-debian-9

00:01:28

passed #25914
amd64
doc

00:01:06

 
  Docker
passed #25917
dind amd64
amd64/lava-dispatcher

00:01:12

passed #25918
dind amd64
amd64/lava-server

00:02:16