Manpages: Don't reference non-existing chroot

Chroot exists neither in code nor in documentation. If we add-in the
feature again, it will be simple enough to add it back in to the
documentation. For now, let's clean it up, instead of refering to things
that don't exist.

Found by markdown-checker.

Base/usr/share/man/man2/mount.md

@@ -72,9 +72,8 @@ to use the new mount flags after remounting a filesystem, a process can call
 `chdir()` with the path to the same directory.
 
 Similarly, to change the mount flags used by the root directory, a process can
-call [`chroot_with_mount_flags`(2)](chroot.md), specifying a single slash (`/`)
-as the path along with the desired flags. While it is possible to remount the
-root filesystem using `MS_REMOUNT`, it would only have a noticeable effect if
+remount the root filesystem using `MS_REMOUNT`.
+However, it only have a noticeable effect if
 the kernel was to launch more userspace processes directly, the way it does
 launch the initial userspace process.
 

Base/usr/share/man/man2/pledge.md

@@ -45,7 +45,6 @@ If the process later attempts to use any system functionality it has previously
 * `dpath`: Creating new device files
 * `chown`: Changing file owner/group
 * `fattr`: Changing file attributes/permissions
-* `chroot`: The [`chroot`(2)](chroot.md) syscall (\*)
 * `video`: May use [`ioctl`(2)](ioctl.md) and [`mmap`(2)](mmap.md) on framebuffer video devices
 * `settime`: Changing the system time and date
 * `setkeymap`: Changing the system keyboard layout (\*)

Base/usr/share/man/man2/unveil.md

@@ -97,5 +97,4 @@ unveil(nullptr, nullptr);
 ## See also
 
 * [`pledge`(2)](pledge.md)
-* [`chroot`(2)](chroot.md)
 * [`Mitigations`(7)](../man7/Mitigations.md)