[PATCH] kbuild: disable header exports for UML in a straightforward way

[Masahiro Yamada]

Previously 'make ARCH=um headers' stopped because of missing
arch/um/include/uapi/asm/Kbuild.

The error is not shown since commit ed102bf2afed ("um: Fix W=1
missing-include-dirs warnings") because UML got
arch/um/include/uapi/asm/Kbuild.

Hard-code the unsupported architecture, so it works like before.

Fixes: ed102bf2afed ("um: Fix W=1 missing-include-dirs warnings")
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

 Makefile | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 9d40255d1557..8d2047a4de9b 100644
--- a/Makefile
+++ b/Makefile
@@ -1304,8 +1304,7 @@ hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
 
 PHONY += headers
 headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
-	$(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
-	  $(error Headers not exportable for the $(SRCARCH) architecture))
+	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
 	$(Q)$(MAKE) $(hdr-inst)=include/uapi
 	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
 
-- 
2.34.1