Documentation: Fix trivial typo in filesystems/sharedsubtree.txt

Documentation: Fix trivial typo in filesystems/sharedsubtree.txt

This typo is easy to ignore unless you have spent a great deal of time
thinking about how to eliminate duplicate dentries in unions.

Signed-off-by: Valerie Aurora <vaurora@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Documentation/filesystems/sharedsubtree.txt

@@ -62,10 +62,10 @@ replicas continue to be exactly same.
 	# mount /dev/sd0  /tmp/a
 
 	#ls /tmp/a
-	t1 t2 t2
+	t1 t2 t3
 
 	#ls /mnt/a
-	t1 t2 t2
+	t1 t2 t3
 
 	Note that the mount has propagated to the mount at /mnt as well.