[source] image.mk: remove leftover variable from a previous rework

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/?p=source.git;a=commitdiff;h=c5a9a08f1ed6d151039a3fac769ca0a333974446

commit c5a9a08f1ed6d151039a3fac769ca0a333974446
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Fri Jul 29 17:13:48 2016 +0200

    image.mk: remove leftover variable from a previous rework
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 include/image.mk | 1 -
 1 file changed, 1 deletion(-)

diff --git a/include/image.mk b/include/image.mk
index 42aa3f0..b5e45ec 100644
--- a/include/image.mk
+++ b/include/image.mk
@@ -422,7 +422,6 @@ define Device/Build/compile
 endef
 
 define Device/Build/kernel
-  _KERNEL_IMAGES += $$(KDIR_KERNEL_NAME)
   $(KDIR)/$$(KERNEL_NAME):: image_prepare
   $$(_TARGET): $$(if $$(KERNEL_INSTALL),$(BIN_DIR)/$$(KERNEL_IMAGE))
   $(call Device/Export,$$(KDIR_KERNEL_IMAGE),$(1))