perf trace: Don't synthesize mmaps unless callchains are enabled

Synthesizing mmaps in perf trace is unnecessary unless call chains are
being generated.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Howard Chu <howardchu95@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Author: captain5050

tools/perf/builtin-trace.c

@@ -2005,7 +2005,9 @@ static int trace__symbols_init(struct trace *trace, int argc, const char **argv,
 
 	err = __machine__synthesize_threads(trace->host, &trace->tool, &trace->opts.target,
 					    evlist->core.threads, trace__tool_process,
-					    true, false, 1);
+					    /*needs_mmap=*/callchain_param.enabled,
+					    /*mmap_data=*/false,
+					    /*nr_threads_synthesize=*/1);
 out:
 	if (err) {
 		perf_env__exit(&trace->host_env);