tracing/selftests: Update synthetic event selftest to use common_stacktrace

With the rename of the stacktrace field to common_stacktrace, update the
selftests to reflect this change. Copy the current selftest to test the
backward compatibility "stacktrace" keyword. Also the "requires" of that
test was incorrect, so it would never actually ran before. That is fixed
now.

Link: https://lore.kernel.org/linux-trace-kernel/20230523225402.55951f2f@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-stack-legacy.tc

+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: event trigger - test inter-event histogram trigger trace action with dynamic string param (legacy stack)
+# requires: set_event synthetic_events events/sched/sched_process_exec/hist "long[] stack' >> synthetic_events":README
+
+fail() { #msg
+    echo $1
+    exit_fail
+}
+
+echo "Test create synthetic event with stack"
+
+# Test the old stacktrace keyword (for backward compatibility)
+echo 's:wake_lat pid_t pid; u64 delta; unsigned long[] stack;' > dynamic_events
+echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=stacktrace  if prev_state == 1||prev_state == 2' >> events/sched/sched_switch/trigger
+echo 'hist:keys=prev_pid:delta=common_timestamp.usecs-$ts,s=$st:onmax($delta).trace(wake_lat,prev_pid,$delta,$s)' >> events/sched/sched_switch/trigger
+echo 1 > events/synthetic/wake_lat/enable
+sleep 1
+
+if ! grep -q "=>.*sched" trace; then
+    fail "Failed to create synthetic event with stack"
+fi
+
+exit 0

tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-stack.tc

 #!/bin/sh
 # SPDX-License-Identifier: GPL-2.0
 # description: event trigger - test inter-event histogram trigger trace action with dynamic string param
-# requires: set_event synthetic_events events/sched/sched_process_exec/hist "long[]' >> synthetic_events":README
+# requires: set_event synthetic_events events/sched/sched_process_exec/hist "can be any field, or the special string 'common_stacktrace'":README
 
 fail() { #msg
     echo $1
@@ -10,9 +10,8 @@ fail() { #msg
 
 echo "Test create synthetic event with stack"
 
-
 echo 's:wake_lat pid_t pid; u64 delta; unsigned long[] stack;' > dynamic_events
-echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=stacktrace  if prev_state == 1||prev_state == 2' >> events/sched/sched_switch/trigger
+echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=common_stacktrace  if prev_state == 1||prev_state == 2' >> events/sched/sched_switch/trigger
 echo 'hist:keys=prev_pid:delta=common_timestamp.usecs-$ts,s=$st:onmax($delta).trace(wake_lat,prev_pid,$delta,$s)' >> events/sched/sched_switch/trigger
 echo 1 > events/synthetic/wake_lat/enable
 sleep 1