[autoboot] Avoid closing and immediately reopening network device

Some network devices can take a substantial time to close and reopen.
Avoid closing the device from which we are about to attempt booting,
in case it happens to be already open.

Suggested-by: Christian Iversen <ci@iversenit.dk>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
1 file changed
tree: f0aa4648d6fd9baf09b85d05e3b7fe9927f3c7eb
  1. contrib/
  2. src/
  3. .travis.yml
  4. COPYING
  5. COPYING.GPLv2
  6. COPYING.UBDL
  7. README