enter_chroot: Modify setup_mount to handle creating files.

A bind mount can be a file and if the destination does not exist
setup_mount used to create a directory instead of a file.

BUG=b:224993207
TEST=cros sdk  # with a new file with a new parent dir in .local_mounts
  # and check the contents to make sure it matches.

Change-Id: Ib5b500a71927e56fbf24b36a522f49a4633fe417
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/3530829
Tested-by: Allen Webb <allenwebb@google.com>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Allen Webb <allenwebb@google.com>
1 file changed