rcu: Don't allow to change rcu_normal_after_boot on RT

[ Upstream commit c6c058c10577815a2491ce661876cff00a4c3b15 ]

On RT rcu_normal_after_boot is enabled by default.
Don't allow to disable it on RT because the "expedited rcu" would
introduce latency spikes.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
17 jobs for ci/pavel/linux-cip in 30 minutes and 35 seconds (queued for 24 seconds)
Status Name Job ID Coverage
  Build
passed build:arm64_moxa_eds_defconfig #457824192

00:07:17

passed build:arm64_renesas_defconfig #457824193

00:08:01

passed build:arm_hitachi_cyclonev_defconfig #457824163

00:07:49

passed build:arm_hitachi_omap_defconfig #457824177

00:10:23

passed build:arm_moxa_mxc_defconfig #457824180

00:11:41

passed build:arm_renesas_shmobile_defconfig #457824185

00:06:52

passed build:arm_siemens_de0-nano-soc_defconfig #457824190

00:06:37

passed build:arm_siemens_imx6.config #457824191

00:08:42

passed build:x86_plathome_obsvx2.config #457824195

00:10:54

passed build:x86_siemens_iot2000.config #457824199

00:12:06

passed build:x86_siemens_ipc227e_defconfig #457824201

00:13:37

passed build:x86_siemens_server_defconfig #457824204

00:12:09

passed build:x86_toshiba_atom_baytrail_cip.config #457824206

00:09:16

 
  Test
failed test:arm64_renesas_defconfig #457824214

00:08:44

passed test:arm_renesas_shmobile_defconfig #457824209

00:07:31

passed test:arm_siemens_de0-nano-soc_defconfig #457824212

00:07:22

passed test:x86_siemens_ipc227e_defconfig #457824215

00:16:35

 
Name Stage Failure
failed
test:arm64_renesas_defconfig Test
------------------------------
Job #12125 Finished. Job health: Incomplete. URL: https://lava.ciplatform.org/scheduler/job/12125
Job #12126 Finished. Job health: Complete. URL: https://lava.ciplatform.org/scheduler/job/12126
Job #12127 Finished. Job health: Complete. URL: https://lava.ciplatform.org/scheduler/job/12127
Job #12128 Finished. Job health: Complete. URL: https://lava.ciplatform.org/scheduler/job/12128
Uploading artifacts...
output: found 20 matching files
Uploading artifacts to coordinator... ok
id=457824214 responseStatus=201 Created token=9caTYagQ
ERROR: Job failed: command terminated with exit code 1