docsrc: fix procfs example

Add MODULE_LICENSE() to DocBook/procfs_example.c since modpost complained
about a missing license there.

Remove tty procfs removal since the creation was deleted long ago
(http://git.kernel.org/?p=linux/kernel/git/tglx/history.git;a=commitdiff;h=5ad9cb65e9b15e5b83e2dd1c10a4bcaccc4ec644).

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: <J.A.K.Mouw@its.tudelft.nl>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>