mount_namespaces.7: wfix: use numbered cross-references in list of restrictions in NOTES

Done to make the list easier to navigate.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man7/mount_namespaces.7

@@ -1045,7 +1045,7 @@ see
 .\"
 .SS Restrictions on mount namespaces
 Note the following points with respect to mount namespaces:
-.IP * 3
+.IP [1] 4
 Each mount namespace has an owner user namespace.
 As explained above, when a new mount namespace is created,
 its mount list is initialized as a copy of the mount list
@@ -1054,13 +1054,13 @@ If the new namespace and the namespace from which the mount list
 was copied are owned by different user namespaces,
 then the new mount namespace is considered
 .IR "less privileged" .
-.IP *
+.IP [2]
 When creating a less privileged mount namespace,
 shared mounts are reduced to slave mounts.
 This ensures that mappings performed in less
 privileged mount namespaces will not propagate to more privileged
 mount namespaces.
-.IP *
+.IP [3]
 Mounts that come as a single unit from a more privileged mount namespace are
 locked together and may not be separated in a less privileged mount
 namespace.
@@ -1148,8 +1148,8 @@ command above, which is performed in the initial mount namespace,
 makes the original
 .I /etc/shadow
 file once more visible in that namespace.
-.IP *
-Following on from the previous point,
+.IP [4]
+Following on from point [3],
 note that it is possible to unmount an entire subtree of mounts that
 propagated as a unit into a less privileged mount namespace,
 as illustrated in the following example.
@@ -1199,7 +1199,7 @@ ns2# \fBgrep /mnt /proc/self/mountinfo | sed \(aqs/ \- .*//\(aq\fP
 .IP
 Of note in the above output is that the propagation type of the mount
 .I /mnt
-has been reduced to slave, as explained near the start of this subsection.
+has been reduced to slave, as explained in point [2].
 This means that submount events will propagate from the master
 .I /mnt
 in "ns1", but propagation will not occur in the opposite direction.
@@ -1261,7 +1261,7 @@ ns2# \fBgrep /mnt /proc/self/mountinfo\fP
 1241 1240 0:57 / /mnt/x/y rw,relatime
 .EE
 .in
-.IP *
+.IP [5]
 The
 .BR mount (2)
 flags
@@ -1301,7 +1301,7 @@ mount: /mnt/dir: permission denied.
 .EE
 .in
 .RE
-.IP *
+.IP [6]
 .\" (As of 3.18-rc1 (in Al Viro's 2014-08-30 vfs.git#for-next tree))
 A file or directory that is a mount point in one namespace that is not
 a mount point in another namespace, may be renamed, unlinked, or removed