Instead of a separate ignore flag, use the obvious DOCBOOKS="" to ignore
all DocBook files. This is also in line with the Sphinx build being
ignored if a non-empty DOCBOOKS make variable is specified on the make
command line.
This replaces the IGNORE_DOCBOOKS introduced in
commit 547218864a
Author: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Date: Sat Jul 9 13:12:45 2016 -0300
doc-rst: add an option to ignore DocBooks when generating docs
and aligns with
commit 6387872c86
Author: Jani Nikula <jani.nikula@intel.com>
Date: Fri Jul 1 15:24:44 2016 +0300
Documentation/sphinx: skip build if user requested specific DOCBOOKS
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>