perf unwind: Fix a compile error

When libunwind is on, there is a compile error as :

  util/unwind-libunwind.c:363:21: error: 'dso' undeclared (first use in this function)
      dso__data_put_fd(dso);

This patch fixes it.
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 4bb11d01 ("perf tools: Add dso__data_get/put_fd()")
Link: http://lkml.kernel.org/r/1434453395-10560-1-git-send-email-houpengyang@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/unwind-libunwind.c

@@ -360,7 +360,7 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
 		unw_word_t base = is_exec ? 0 : map->start;
 
 		if (fd >= 0)
-			dso__data_put_fd(dso);
+			dso__data_put_fd(map->dso);
 
 		memset(&di, 0, sizeof(di));
 		if (dwarf_find_debug_frame(0, &di, ip, base, map->dso->name,