[PATCH 1/3] rt-tests: README: Remove obsolete -n option from cyclictest examples

The -n/--nanosleep option was removed from cyclictest in commit
9d2c9edd8694 ("cyclictest: make clock_nanosleep as default and add
option for POSIX timers") in March 2017.

Since then, clock_nanosleep has been the default behavior, making the
-n option redundant. The examples in README.markdown still referenced
this obsolete option, causing the commands to fail with "invalid option".

Update all cyclictest example commands to remove the -n flag.

Also add SPDX-License-Identifier to match project conventions.

Assisted-by: Claude:claude-sonnet-4-5
Signed-off-by: John Kacur <[email protected]>
---
 README.markdown | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/README.markdown b/README.markdown
index 617b57e88614..9e6ec20e036c 100644
--- a/README.markdown
+++ b/README.markdown
@@ -1,3 +1,5 @@
+SPDX-License-Identifier: GPL-2.0-or-later
+
 # RT-Tests
 
 This repository contains some programs that test various rt-linux features.
@@ -14,7 +16,7 @@ This repository contains some programs that test various rt-linux features.
 To run one test thread per CPU or per CPU core, each thread on a separate
 processor, type
 
-    sudo ./cyclictest -a -t -n -p99
+    sudo ./cyclictest -a -t -p99
 
 On a non-realtime system, you may see something like
 
@@ -62,7 +64,7 @@ tracer must be configured upfront. The resulting trace can be invastigated in
 `/sys/kernel/tracing/trace`, for example:
 
     echo function > /sys/kernel/tracing/current_tracer
-    cyclictest -a -t -n -p99 --tracemark --breaktrace 100
+    cyclictest -a -t -p99 --tracemark --breaktrace 100
 
 This causes the program to abort execution, if the latency value exceeds 100
 microseconds; the culprit can then be found in the trace output at
-- 
2.54.0