core: remove dependencies on genext2fs

We don't use EXT2 for bootimage anymore.
This will allow getting rid of external/genext2fs

Bug: 19282953
Change-Id: Ie56528c7877036d2501a09888a4420637f9cd647
diff --git a/core/Makefile b/core/Makefile
index 85c575b..e52fbc8 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -486,18 +486,7 @@
 INSTALLED_BOOTIMAGE_TARGET := $(PRODUCT_OUT)/boot.img
 
 ifeq ($(TARGET_BOOTIMAGE_USE_EXT2),true)
-tmp_dir_for_image := $(call intermediates-dir-for,EXECUTABLES,boot_img)/bootimg
-INTERNAL_BOOTIMAGE_ARGS += --tmpdir $(tmp_dir_for_image)
-INTERNAL_BOOTIMAGE_ARGS += --genext2fs $(MKEXT2IMG)
-$(INSTALLED_BOOTIMAGE_TARGET): $(MKEXT2IMG) $(INTERNAL_BOOTIMAGE_FILES)
-	$(call pretty,"Target boot image: $@")
-	$(hide) $(MKEXT2BOOTIMG) $(INTERNAL_BOOTIMAGE_ARGS) --output $@
-
-.PHONY: bootimage-nodeps
-bootimage-nodeps: $(MKEXT2IMG)
-	@echo "make $@: ignoring dependencies"
-	$(hide) $(MKEXT2BOOTIMG) $(INTERNAL_BOOTIMAGE_ARGS) --output $(INSTALLED_BOOTIMAGE_TARGET)
-
+$(error TARGET_BOOTIMAGE_USE_EXT2 is not supported anymore)
 else ifeq (true,$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY)) # TARGET_BOOTIMAGE_USE_EXT2 != true
 
 $(INSTALLED_BOOTIMAGE_TARGET): $(MKBOOTIMG) $(INTERNAL_BOOTIMAGE_FILES) $(BOOT_SIGNER)