x86: add_drv, update_drv, and rem_drv Commands Should Use Advisory Record Locking (6445040)

The update_drv command does not remove the /tmp/AdDrEm.lck lock file immediately, resulting in subsequent add_drv, update_drv, and rem_drv commands to fail. This issue is mostly visible when creating a custom install image. This lock file has been bundled in the miniroot so any attempts to add a package will fail. The following error message is displayed:

add_drv/rem_drv currently busy; try later

Workaround: If the /tmp/AdDrEm.lck file exists, manually remove it before attempting a pkgadd or *_drv commands.