Allow simple quoting of words in the dynamic debug control language.

This allows more natural specification when using the control language
to match against printk formats, e.g

#echo -n 'format "Setting node for non-present cpu" +p' >
	/mnt/debugfs/dynamic_debug/control

instead of

#echo -n 'format Setting\040node\040for\040non-present\040cpu +p' >
	/mnt/debugfs/dynamic_debug/control

Adjust the dynamic debug documention to describe that and provide a
new example.  Adjust the existing examples in the documentation to
reflect the current whitespace escaping behaviour when reading the
control file.  Fix some minor documentation trailing whitespace.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Acked-by: NJason Baron <jbaron@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>