package/kernel/linux: only access kernel config if DUMP is unset

Signed-off-by: Felix Fietkau <nbd@nbd.name>

package/kernel/linux/Makefile

@@ -23,9 +23,8 @@ export SHELL:=/bin/sh
 
 include $(INCLUDE_DIR)/package.mk
 
-STAMP_BUILT:=$(STAMP_BUILT)_$(firstword $(shell $(SCRIPT_DIR)/kconfig.pl $(LINUX_DIR)/.config | md5sum))
-
 ifeq ($(DUMP),)
+  STAMP_BUILT:=$(STAMP_BUILT)_$(firstword $(shell $(SCRIPT_DIR)/kconfig.pl $(LINUX_DIR)/.config | md5sum))
   -include $(LINUX_DIR)/.config
 endif