kbuild: disable header exports for UML in a straightforward way

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

The error is not shown since commit af70e7fa8db5 ("um: Fix W=1
missing-include-dirs warnings") added arch/um/include/uapi/asm/Kbuild.

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

Fixes: af70e7fa8db5 ("um: Fix W=1 missing-include-dirs warnings")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Richard Weinberger <richard@nod.at>

diff --git a/Makefile b/Makefile
index 952d354069a43f0c269e1ad662a08f89d06fd6ad..85e3c9f55bde3f5aad3341e7502e5099f7f63e3e 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1287,8 +1287,7 @@ 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