[openwrt/openwrt] bpf-headers: Fix download URL with kernel 6.1

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/a15eb1cda05d1a74146deb98edc61f0861c46852

commit a15eb1cda05d1a74146deb98edc61f0861c46852
Author: Hauke Mehrtens <hauke at hauke-m.de>
AuthorDate: Mon Nov 6 01:30:31 2023 +0100

    bpf-headers: Fix download URL with kernel 6.1
    
    This fixes the download of the kernel 5.15 for the bpf-headers when
    kernel 6.1 is build for the target.
    
    Even if kernel 6.1 was selected for the target we still use kernel 5.15
    for the bpf-headers. The download script tried to download the 5.15
    kernel from the 6.x directory on kernel,org and this failed. Define
    PKG_SOURCE_URL based on PKG_PATCHVER and not KERNEL_BASE like done in
    kernel.mk.
    
    Without this change it tries to download the kernel from this URL:
    ttps://cdn.kernel.org/pub/linux/kernel/v6.x/linux-5.15.129.tar.xz
    
    Fixes: #13190
    Fixes: #13671
    Fixes: #13814
    Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
---
 package/kernel/bpf-headers/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package/kernel/bpf-headers/Makefile b/package/kernel/bpf-headers/Makefile
index 733f358672..5efd2e1cf0 100644
--- a/package/kernel/bpf-headers/Makefile
+++ b/package/kernel/bpf-headers/Makefile
@@ -19,7 +19,7 @@ include $(INCLUDE_DIR)/kernel-$(PKG_PATCHVER)
 
 PKG_VERSION:=$(PKG_PATCHVER)$(strip $(LINUX_VERSION-$(PKG_PATCHVER)))
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
-PKG_SOURCE_URL:=$(LINUX_SITE)
+PKG_SOURCE_URL:=@KERNEL/linux/kernel/v$(word 1,$(subst ., ,$(PKG_PATCHVER))).x
 PKG_HASH:=$(LINUX_KERNEL_HASH-$(strip $(PKG_VERSION)))
 PKG_BUILD_DIR:=$(KERNEL_BUILD_DIR)/bpf-headers/$(PKG_NAME)-$(PKG_VERSION)