[PATCH] scripts/kconfig/Makefile: use KCONFIG_CONFIG if set

[Arseny Maslennikov]

In a kernel source tree:

% make mrproper
% make KCONFIG_CONFIG=.myconfig kvmconfig'
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
  HOSTCC  scripts/kconfig/confdata.o
  HOSTCC  scripts/kconfig/expr.o
  HOSTCC  scripts/kconfig/symbol.o
  HOSTCC  scripts/kconfig/preprocess.o
  LEX     scripts/kconfig/zconf.lex.c
  YACC    scripts/kconfig/zconf.tab.h
  HOSTCC  scripts/kconfig/zconf.lex.o
  YACC    scripts/kconfig/zconf.tab.c
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf
The base file '.config' does not exist.  Exit.
make[1]: *** [scripts/kconfig/Makefile:96: kvm_guest.config] Error 1
make: *** [Makefile:538: kvmconfig] Error 2

Essentially `make kvmconfig' (and probably other similar targets)
did ignore KCONFIG_CONFIG set to a different filename.

If KCONFIG_CONFIG is set, use it; otherwise behave as if it was set
to `.config'.

Signed-off-by: Arseny Maslennikov <ar@xxxxxxxxx>
---
 scripts/kconfig/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
index 181973509a05..1c7ac07def4d 100644
--- a/scripts/kconfig/Makefile
+++ b/scripts/kconfig/Makefile
@@ -93,7 +93,7 @@ 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)/scripts/kconfig/merge_config.sh -m .config $(configfiles)
+	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh -m $(KCONFIG_CONFIG) $(configfiles)
 	+$(Q)yes "" | $(MAKE) -f $(srctree)/Makefile oldconfig
 
 PHONY += kvmconfig
-- 
2.20.1