kbuild: do not create built-in objects for external module builds
'make M=/path/to/your/external/module' creates a pointless built-in.a
in the top of the external module directory because KBUILD_BUILTIN is
set to 1.
Clear KBUILD_BUILTIN when we are building external modules so that
'make M=...' and 'make M=... modules' work equivalently.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
diff --git a/Makefile b/Makefile
index 97b1dae..744b6c66 100644
--- a/Makefile
+++ b/Makefile
@@ -1702,7 +1702,8 @@
# Install the modules built in the module directory
# Assumes install directory is already created
-# We are always building modules
+# We are always building only modules.
+KBUILD_BUILTIN :=
KBUILD_MODULES := 1
build-dirs := $(KBUILD_EXTMOD)