ClatdController - fix dump unique_fd double ownership

Should hopefully fix:
  Abort message: 'failed to exchange ownership of file descriptor: fd ... is owned by unique_fd 0x..., was expected to be unowned'

Test: atest netd_unit_test
Bug: 65674744
Bug: 129654883
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ide661bb6521673d272654e969360ce3aa4bdff5d