selftests/ftrace: check for do_sys_openat2 in user-memory test

More recent libc implementations are now using openat/openat2 system
calls so also add do_sys_openat2 to the tracing so that the test
passes on these systems because do_sys_open may not be called.

Thanks to Masami Hiramatsu for the help on getting this fix to work
correctly.

Signed-off-by: Colin Ian King <[e-mail]>
Acked-by: Masami Hiramatsu <[e-mail]>
Acked-by: Steven Rostedt (VMware) <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc

···
 :;: "user-memory access syntax and ustring working on user memory";:
 echo 'p:myevent do_sys_open path=+0($arg2):ustring path2=+u0($arg2):string' \
 	> kprobe_events
+echo 'p:myevent2 do_sys_openat2 path=+0($arg2):ustring path2=+u0($arg2):string' \
+	>> kprobe_events
 
 grep myevent kprobe_events | \
 	grep -q 'path=+0($arg2):ustring path2=+u0($arg2):string'
 echo 1 > events/kprobes/myevent/enable
+echo 1 > events/kprobes/myevent2/enable
 echo > /dev/null
 echo 0 > events/kprobes/myevent/enable
+echo 0 > events/kprobes/myevent2/enable
 
 grep myevent trace | grep -q 'path="/dev/null" path2="/dev/null"'