Docs: Document that the sticky bit is understood by hugetlbfs

Commit 75897d60 (hugetlb: allow sticky directory mount option) added
support for mounting hugetlbfs with sticky option set, like /tmp is
usually mounted, but forgot to document that.

Acked-by: Ken Chen <kenchen@google.com>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/vm/hugetlbpage.txt

@@ -274,7 +274,7 @@ This command mounts a (pseudo) filesystem of type hugetlbfs on the directory
 /mnt/huge.  Any files created on /mnt/huge uses huge pages.  The uid and gid
 options sets the owner and group of the root of the file system.  By default
 the uid and gid of the current process are taken.  The mode option sets the
-mode of root of file system to value & 0777.  This value is given in octal.
+mode of root of file system to value & 01777.  This value is given in octal.
 By default the value 0755 is picked. The size option sets the maximum value of
 memory (huge pages) allowed for that filesystem (/mnt/huge). The size is
 rounded down to HPAGE_SIZE.  The option nr_inodes sets the maximum number of