perf disasm: Fix potential use-after-free on fileloc

perf disasm: Fix potential use-after-free on fileloc

The fileloc is a copy of a pointer to a string but in places like
symbol_disassemble__llvm this string appears to be freed setting up
potential use-after-frees:

llvm.c:
```
		dl = disasm_line__new(args);
		if (dl == NULL)
			goto err;

		annotation_line__add(&dl->al, &notes->src->source);

		free(args->fileloc);
```

disasm.c:
```
static void annotation_line__init(struct annotation_line *al,
				  struct annotate_args *args,
				  int nr)
{
	al->offset = args->offset;
	al->line = strdup(args->line);
	al->line_nr = args->line_nr;
	al->fileloc = args->fileloc;
	al->data_nr = nr;
}

struct disasm_line *disasm_line__new(struct annotate_args *args)
{
	struct disasm_line *dl = NULL;
	struct annotation *notes = symbol__annotation(args->ms->sym);
	int nr = notes->src->nr_events;

	dl = zalloc(disasm_line_size(nr));
	if (!dl)
		return NULL;

	annotation_line__init(&dl->al, args, nr);
```

Fix this by making the fileloc a copy of the underlying string in its
init/exit.

Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>