VFS_UNMOUNT(9) on FreeBSD

The text b695b9088862, as FreeBSD 4.4-RELEASE, FreeBSD 4.3-RELEASE, FreeBSD 4.2-RELEASE, FreeBSD 4.1.1-RELEASE, FreeBSD 4.1-RELEASE, FreeBSD 4.0-RELEASE shipped it.

unmount a filesystem

VFS_UNMOUNT(9) on FreeBSD now