[openwrt/openwrt] iproute2: Fix KERNEL_INCLUDE in SDK

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/60738fedede1746922a8b227f24ad5c733661585

commit 60738fedede1746922a8b227f24ad5c733661585
Author: Hauke Mehrtens <hauke at hauke-m.de>
AuthorDate: Tue Aug 16 23:38:52 2022 +0200

    iproute2: Fix KERNEL_INCLUDE in SDK
    
    In the SDK the folder $(LINUX_DIR)/user_headers/include does not exist,
    but it more or less contains the same content as
    $(LINUX_DIR)/include/uapi which also exists in the SDK.
    
    Since iproute2 commit 1d819dcc741e ("configure: fix parsing issue on
    include_dir option") it checks if this folder exists and aborts the
    build if it does not exists.
    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=1d819dcc741e25958190e31f8186c940713fa0a8
    
    With this commit the KERNEL_INCLUDE variable points to a valid folder
    with the kernel include headers. I am not sure if they are actually
    needed because the build worked before even with an invalid path.
    
    Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
---
 package/network/utils/iproute2/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package/network/utils/iproute2/Makefile b/package/network/utils/iproute2/Makefile
index 5439c050c1..4c21d4d877 100644
--- a/package/network/utils/iproute2/Makefile
+++ b/package/network/utils/iproute2/Makefile
@@ -176,7 +176,7 @@ TARGET_LDFLAGS += -Wl,--gc-sections -Wl,--as-needed
 TARGET_CPPFLAGS += -I$(STAGING_DIR)/usr/include/libnl-tiny
 
 MAKE_FLAGS += \
-	KERNEL_INCLUDE="$(LINUX_DIR)/user_headers/include" \
+	KERNEL_INCLUDE="$(LINUX_DIR)/include/uapi" \
 	SHARED_LIBS=$(SHARED_LIBS) \
 	IP_CONFIG_TINY=$(IP_CONFIG_TINY) \
 	BUILD_VARIANT=$(BUILD_VARIANT) \