selftests/ftrace: Convert required interface checks into requires list

Convert the required tracefs interface checking code with
requires: list.

Fixed merge conflicts in trigger-hist.tc and trigger-trace-marker-hist.tc
Shuah Khan <skhan@linuxfoundation.org>

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/ftrace: Distinguish between hist and synthetic event checks

With synthetic events now a separate config item as a result of
'tracing: Move synthetic events to a separate file', tests that use
both need to explicitly check for hist trigger support rather than
relying on hist triggers to pull in synthetic events.

Add an additional hist trigger check to all the trigger tests that now
require it, otherwise they'll fail if synthetic events but not hist
triggers are enabled.

Link: http://lkml.kernel.org/r/af36c539006ef2768114b4ed38e6b054f7c7a3bd.1590693308.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Add SPDX license GPL-2.0 license identifier to inter-event testcases

Apparently this directory was missed in the license cleanup process -
add the missing identifiers to the trigger/inter-event test cases.

Link: http://lkml.kernel.org/r/6f9828c2cfb0b378ebd217a39a1b44f063fc17fb.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

selftests/ftrace: Remove unneeded per-test init/cleanup ftrace

Since ftracetest framework calls initialize_ftrace() right before
each test and after all tests, we don't need to init/cleanup
ftrace for each test case.
Just remove such unneeded init/cleanup code because it can
increase logfile size.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>

selftests: ftrace: Add a testcase for multiple actions on trigger

Add a testcase for multiple actions with different
parameters on an event trigger, which has been fixed
by commit 192c283e93bd ("tracing: Add action comparisons
when testing matching hist triggers").

Link: http://lkml.kernel.org/r/152292055227.15769.6327959816123227152.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>