[XEN PATCH v2] xen/build: use the correct kconfig makefile

[Stewart Hildebrand <stewart.hildebrand@xxxxxxxxxxxxxxx>]

This resolves the following observed error during config merge:

/bin/sh /path/to/xen/xen/../xen/tools/kconfig/merge_config.sh -m .config 
/path/to/xen/xen/../xen/arch/arm/configs/custom.config
Using .config as base
Merging /path/to/xen/xen/../xen/arch/arm/configs/custom.config
#
# merged configuration written to .config (needs make)
#
make -f /path/to/xen/xen/../xen/Makefile olddefconfig
make[2]: Entering directory '/path/to/xen/xen'
make[2]: *** No rule to make target 'olddefconfig'.  Stop.
make[2]: Leaving directory '/path/to/xen/xen'
tools/kconfig/Makefile:95: recipe for target 'custom.config' failed

The build was invoked by first doing a defconfig (which succeeded):

$ make -C xen XEN_TARGET_ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig

Followed by the config fragment merge command (which failed before this patch)

$ cat > xen/arch/arm/configs/custom.config <<EOF
CONFIG_DEBUG=y
CONFIG_EARLY_PRINTK_ZYNQMP=y
EOF
$ make -C xen XEN_TARGET_ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- 
custom.config

Signed-off-by: Stewart Hildebrand <stewart.hildebrand@xxxxxxxxxxxxxxx>

---
v2: updated commit message
---
 xen/tools/kconfig/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/tools/kconfig/Makefile b/xen/tools/kconfig/Makefile
index fd37f4386a..f39521a0ed 100644
--- a/xen/tools/kconfig/Makefile
+++ b/xen/tools/kconfig/Makefile
@@ -94,7 +94,7 @@ configfiles=$(wildcard $(srctree)/kernel/configs/$@ 
$(srctree)/arch/$(SRCARCH)/c
 %.config: $(obj)/conf
        $(if $(call configfiles),, $(error No configuration exists for this 
target on this architecture))
        $(Q)$(CONFIG_SHELL) $(srctree)/tools/kconfig/merge_config.sh -m .config 
$(configfiles)
-       $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
+       $(Q)$(MAKE) -f $(srctree)/tools/kconfig/Makefile.kconfig olddefconfig
 
 PHONY += kvmconfig
 kvmconfig: kvm_guest.config
-- 
2.26.2