perf strlist: Make dupstr be the default and part of an extensible config parm

So that we can pass more info to strlist__new() without having to change
its function signature, just adding entries to the strlist_config struct
with sensible defaults for when those fields are not specified.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-5uaaler4931i0s9sedxjquhq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-trace.c

@@ -2931,7 +2931,7 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
 		trace.not_ev_qualifier = *s == '!';
 		if (trace.not_ev_qualifier)
 			++s;
-		trace.ev_qualifier = strlist__new(true, s);
+		trace.ev_qualifier = strlist__new(s, NULL);
 		if (trace.ev_qualifier == NULL) {
 			fputs("Not enough memory to parse event qualifier",
 			      trace.output);