kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS

Accumulate subdir-{cc,as}flags-y directly to KBUILD_{A,C}FLAGS.
Remove KBUILD_SUBDIR_{AS,CC}FLAGS.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Cao jin <caoj.fnst@cn.fujitsu.com>

scripts/Makefile.lib

@@ -5,8 +5,8 @@ cppflags-y += $(EXTRA_CPPFLAGS)
 ldflags-y  += $(EXTRA_LDFLAGS)
 
 # flags that take effect in current and sub directories
-export KBUILD_SUBDIR_ASFLAGS := $(KBUILD_SUBDIR_ASFLAGS) $(subdir-asflags-y)
-export KBUILD_SUBDIR_CCFLAGS := $(KBUILD_SUBDIR_CCFLAGS) $(subdir-ccflags-y)
+KBUILD_AFLAGS += $(subdir-asflags-y)
+KBUILD_CFLAGS += $(subdir-ccflags-y)
 
 # Figure out what we need to build from the various variables
 # ===========================================================================
@@ -94,10 +94,10 @@ basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
 modname_flags  = $(if $(filter 1,$(words $(modname))),\
                  -DKBUILD_MODNAME=$(call name-fix,$(modname)))
 
-orig_c_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \
+orig_c_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) \
                  $(ccflags-y) $(CFLAGS_$(basetarget).o)
 _c_flags       = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags))
-orig_a_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \
+orig_a_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) \
                  $(asflags-y) $(AFLAGS_$(basetarget).o)
 _a_flags       = $(filter-out $(AFLAGS_REMOVE_$(basetarget).o), $(orig_a_flags))
 _cpp_flags     = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))