Give run_test.sh location of the kernel for CrosVM tests

The output directory location can be overridden, eg on build servers,
but the build rules for CrosVM hello world tests assumed it was always
in the default location '<root>/out'.

Change-Id: I50f8de33dfa8d6dd033bebe510812769b568dec5
diff --git a/Makefile b/Makefile
index eadf682..a9b3745 100644
--- a/Makefile
+++ b/Makefile
@@ -323,6 +323,7 @@
 
 define gen_crosvm_helloworld_test
 	$(KUT_RUN_TEST) -d $(1) $(2) \
+		-k $(KERNEL_IMAGE) \
 		-o $(CROSVM_HELLOWORLD_LOG_DIR)/$(1).log \
 		$(CROSVM_HELLOWORLD_SCRIPT_DIR)/host.sh -- \
 		-R $(CROSVM_HELLOWORLD_SCRIPT_DIR)/guest.sh \