[openwrt/openwrt] kernel: Make KERNEL_MAKEOPTS recursively expanded

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch openwrt-22.03:
https://git.openwrt.org/709351bf328f7173cecc0c065c46151ae45804bd

commit 709351bf328f7173cecc0c065c46151ae45804bd
Author: Hauke Mehrtens <hmehrtens at maxlinear.com>
AuthorDate: Wed Dec 14 16:29:16 2022 +0100

    kernel: Make KERNEL_MAKEOPTS recursively expanded
    
    KERNEL_MAKEOPTS will get expanded when it is used and not when it is
    defined in the kernel.mk file now. This fixes problems finding dependent
    kernel modules when it is used by a kernel module package.
    
    Without this change the build of packages which depend on other out of
    tree modules failed when they used KERNEL_MAKE because some symbols could
    not be found. This happened because KERNEL_MAKE_FLAGS which contains a
    "if $(__package_mk)" was  evaluated where KERNEL_MAKEOPTS was defined
    and not when the KERNEL_MAKE was used. For packages which included
    kernel.mk before package.mk we saw this problem. One workaround
    was to use the correct include order and the other one was to not
    use KERNEL_MAKE_FLAGS, but copy its content.
    
    Signed-off-by: Hauke Mehrtens <hmehrtens at maxlinear.com>
    (cherry picked from commit 06ad3adeecc27859313e60c173c435d45ac2b345)
---
 include/kernel.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/kernel.mk b/include/kernel.mk
index 070d1bca75..d61e0c2677 100644
--- a/include/kernel.mk
+++ b/include/kernel.mk
@@ -126,7 +126,7 @@ ifeq ($(call qstrip,$(CONFIG_EXTERNAL_KERNEL_TREE))$(call qstrip,$(CONFIG_KERNEL
 	KERNELRELEASE=$(LINUX_VERSION)
 endif
 
-KERNEL_MAKEOPTS := -C $(LINUX_DIR) $(KERNEL_MAKE_FLAGS)
+KERNEL_MAKEOPTS = -C $(LINUX_DIR) $(KERNEL_MAKE_FLAGS)
 
 ifdef CONFIG_USE_SPARSE
   KERNEL_MAKEOPTS += C=1 CHECK=$(STAGING_DIR_HOST)/bin/sparse