This patch avoids that the following warning is reported when building
against kernel v4.21:
================= WARNING ================
'SUBDIRS' will be removed after Linux 5.3
Please use 'M=' or 'KBUILD_EXTMOD' instead
==========================================
A quote from an upstream kernel patch:
commit 07e5823127155b3a29003aca926f87c9843f6810
Author: Andrew Morton <akpm@osdl.org>
Date: Mon Apr 12 01:05:40 2004 -0700
[PATCH] kbuild: external module support
From: Sam Ravnborg <sam@ravnborg.org>
Based on initial patch from Andreas Gruenbacher there is now better support
for building external modules with kbuild.
The preferred syntax is now:
make -C $KERNELSRC M=$PWD
but the old syntax:
make -C $KERNELSRC SUBDIRS=$PWD modules
will remain supported.
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@7851 d57e44dd-8a1f-0410-8b47-8ef2f437770f
d3e2f5ab99