The generated wrappers will ignore the raw fields and will only consider the
shortcut fields. This function takes the raw fields and serializes them
instead.
Use a pointer, so it's explicit and gcc is happy. We avoid the
allocation by pointing it to another stack var.
./wire/tlvstream.c:81:22: error: ‘prev_type’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
