perf machine: Fix missing free of machine->kallsyms_filename

Add missing free of machine->kallsyms_filename to machine__exit().

Fixes: a5367ecb ("perf tools: Automatically use guest kcore_dir if present")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220809130758.12800-1-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/machine.c

@@ -236,6 +236,7 @@ void machine__exit(struct machine *machine)
 	zfree(&machine->root_dir);
 	zfree(&machine->mmap_name);
 	zfree(&machine->current_tid);
+	zfree(&machine->kallsyms_filename);
 
 	for (i = 0; i < THREADS__TABLE_SIZE; i++) {
 		struct threads *threads = &machine->threads[i];