klp-build: Print "objtool klp diff" command in verbose mode

Print the full objtool command line when '--verbose' is given to help
with debugging.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

scripts/livepatch/klp-build

@@ -681,6 +681,7 @@ diff_objects() {
 
 		(
 			cd "$ORIG_DIR"
+			[[ -v VERBOSE ]] && echo "cd $ORIG_DIR && ${cmd[*]}"
 			"${cmd[@]}"							\
 				1> >(tee -a "$log")					\
 				2> >(tee -a "$log" | "${filter[@]}" >&2) ||		\