[source] ar71xx: fix build error when initramfs is disabled

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/?p=source.git;a=commitdiff;h=70cf8c304851f58c8411c8053954cdefcf9f234a

commit 70cf8c304851f58c8411c8053954cdefcf9f234a
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Wed Jul 13 18:34:52 2016 +0200

    ar71xx: fix build error when initramfs is disabled
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 target/linux/ar71xx/image/legacy.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/linux/ar71xx/image/legacy.mk b/target/linux/ar71xx/image/legacy.mk
index 680dece..b9a7f13 100644
--- a/target/linux/ar71xx/image/legacy.mk
+++ b/target/linux/ar71xx/image/legacy.mk
@@ -1156,7 +1156,7 @@ endef
 
 define Image/Build/Profile
 	$(call Image/Build/Profile/$(1),buildkernel)
-	$(call Image/Build/Profile/$(1),initramfs)
+	$(if $(CONFIG_TARGET_ROOTFS_INITRAMFS),$(call Image/Build/Profile/$(1),initramfs))
 	$(call Image/Build/Profile/$(1),$(2))
 endef