[openwrt/openwrt] arptables: add CPPFLAGS

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch openwrt-25.12:
https://git.openwrt.org/5884c75aadd775f6646d0bdb2471ac33f125a15b

commit 5884c75aadd775f6646d0bdb2471ac33f125a15b
Author: Hauke Mehrtens <hauke at hauke-m.de>
AuthorDate: Tue Feb 17 22:22:07 2026 +0100

    arptables: add CPPFLAGS
    
    Add the OpenWrt CPPFLAGS to the CFLAGS. arptables does not
    support CPPFLAGS. This fixes fortify sources support.
    
    Link: https://github.com/openwrt/openwrt/pull/22056
    Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
    (cherry picked from commit 33b2c6f955fb2a088f582f84871b05fc9db5e11c)
---
 package/network/utils/arptables/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package/network/utils/arptables/Makefile b/package/network/utils/arptables/Makefile
index 7f32ed1395..260824359a 100644
--- a/package/network/utils/arptables/Makefile
+++ b/package/network/utils/arptables/Makefile
@@ -31,7 +31,7 @@ define Package/arptables-legacy
 endef
 
 MAKE_FLAGS += \
-	COPT_FLAGS="$(TARGET_CFLAGS) -D__OPTIMIZE__=1" \
+	COPT_FLAGS="$(TARGET_CFLAGS) $(TARGET_CPPFLAGS) -D__OPTIMIZE__=1" \
 	KERNEL_DIR="$(LINUX_DIR)"
 
 define Package/arptables-legacy/install