[build] Fix the issue about python3 not found

Change-Id: Ie1e26c4d5f2beac39d3078336daf7eef8df1f271
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/yasm/+/948173
Reviewed-by: Petr Hosek <phosek@google.com>
1 file changed