[Crash-utility] [PATCH] memory_driver: Fix memory driver module build with Linux 5.4 and later

[HAGIO KAZUHITO(萩尾 一仁)]

With Linux 5.4 and later kernels that contain commit
7e35b42591c058b91282f95ce3b2cf0c05ffe93d ("kbuild: remove SUBDIRS
support"), "make" command in the memory_driver directory doesn't
build crash memory driver module as expected.  Add "M=" to fix.

Signed-off-by: Kazuhito Hagio <k-hagio-ab at nec.com>
---
 memory_driver/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/memory_driver/Makefile b/memory_driver/Makefile
index e84afe98ff24..b494aa3cd184 100644
--- a/memory_driver/Makefile
+++ b/memory_driver/Makefile
@@ -10,6 +10,6 @@
 #
 obj-m := crash.o
 all:
-	make -C /lib/modules/`uname -r`/build SUBDIRS=${PWD} modules
+	make -C /lib/modules/`uname -r`/build M=${PWD} SUBDIRS=${PWD} modules
 clean:
 	rm -f *.mod.c *.ko *.o Module.*