kbuild: userprogs: avoid duplication of flags inherited from kernel

The duplication makes maintenance harder. Changes need to be done in two
places and the lines will grow overly long.

Use an intermediary variable instead.

Signed-off-by: Thomas Weißschuh <[email protected]>
Reviewed-by: Nicolas Schier <[email protected]>
Acked-by: Masahiro Yamada <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Nathan Chancellor <[email protected]>

Author: t-8ch

Makefile

@@ -1135,8 +1135,9 @@ LDFLAGS_vmlinux	+= --emit-relocs --discard-none
 endif
 
 # Align the bit size of userspace programs with the kernel
-KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
-KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
+USERFLAGS_FROM_KERNEL := -m32 -m64 --target=%
+KBUILD_USERCFLAGS  += $(filter $(USERFLAGS_FROM_KERNEL), $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
+KBUILD_USERLDFLAGS += $(filter $(USERFLAGS_FROM_KERNEL), $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
 
 # userspace programs are linked via the compiler, use the correct linker
 ifdef CONFIG_CC_IS_CLANG