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>
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 7ff6827..d0bf1e5 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -250,7 +250,7 @@
 			static struct strlist *seen;
 
 			if (!seen)
-				seen = strlist__new(true, NULL);
+				seen = strlist__new(NULL, NULL);
 
 			if (!strlist__has_entry(seen, path)) {
 				pr_err("Can't access file %s\n", path);