[openwrt/openwrt] image: fix CONFIG_EXTERNAL_CPIO handling

[LEDE Commits]

dangole pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/0a4f5d06c23215f4ea9945f8d72dff5ba60c34e5

commit 0a4f5d06c23215f4ea9945f8d72dff5ba60c34e5
Author: Daniel Golle <daniel at makrotopia.org>
AuthorDate: Sat Nov 27 12:02:05 2021 +0000

    image: fix CONFIG_EXTERNAL_CPIO handling
    
    CONFIG_EXTERNAL_CPIO is a string variable, hence testing for 'y'
    doesn't make much sense here.
    
    Fixes: 330bd380e8 ("image: allow building FIT and uImage with ramdisk")
    Reported-by: Huangbin Zhan <zhanhb88 at gmail.com>
    Signed-off-by: Daniel Golle <daniel at makrotopia.org>
---
 include/kernel-defaults.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/kernel-defaults.mk b/include/kernel-defaults.mk
index 77a612dbe1..5a061a5178 100644
--- a/include/kernel-defaults.mk
+++ b/include/kernel-defaults.mk
@@ -171,7 +171,7 @@ define Kernel/CompileImage/Initramfs
 	$(if $(SOURCE_DATE_EPOCH),touch -hcd "@$(SOURCE_DATE_EPOCH)" $(TARGET_DIR)/init)
 	rm -rf $(KERNEL_BUILD_DIR)/linux-$(LINUX_VERSION)/usr/initramfs_data.cpio*
 ifeq ($(CONFIG_TARGET_ROOTFS_INITRAMFS_SEPARATE),y)
-ifeq ($(CONFIG_EXTERNAL_CPIO),y)
+ifneq ($(qstrip $(CONFIG_EXTERNAL_CPIO)),)
 	$(CP) $(CONFIG_EXTERNAL_CPIO) $(KERNEL_BUILD_DIR)/initrd.cpio
 else
 	( cd $(TARGET_DIR); find . | $(STAGING_DIR_HOST)/bin/cpio -o -H newc -R 0:0 > $(KERNEL_BUILD_DIR)/initrd.cpio )