wire/test: remove unused padding code.

Turns out the peer part of the spec no longer uses padding (it's used only
in the onion), and GCC-9 with -O3 warns we're padding NULL to memcpy.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

wire/test/run-peer-wire.c

@@ -1,15 +1,8 @@
 #include "../gen_peer_wire.c"
 
-void towire_pad_orig(u8 **pptr, size_t num);
-#define towire_pad towire_pad_orig
-void fromwire_pad_orig(const u8 **cursor, size_t *max, size_t num);
-#define towire_pad towire_pad_orig
-#define fromwire_pad fromwire_pad_orig
 #include "../towire.c"
 #include "../fromwire.c"
 #include "../peer_wire.c"
-#undef towire_pad
-#undef fromwire_pad
 
 #include <assert.h>
 #include <stdio.h>
@@ -21,19 +14,6 @@ secp256k1_context *secp256k1_ctx;
 /* AUTOGENERATED MOCKS START */
 /* AUTOGENERATED MOCKS END */
 
-/* We allow non-zero padding for testing. */
-static const void *towire_pad_arr;
-void towire_pad(u8 **pptr, size_t num)
-{
-	towire_u8_array(pptr, towire_pad_arr, num);
-}
-
-static void *fromwire_pad_arr;
-void fromwire_pad(const u8 **cursor, size_t *max, size_t num)
-{
-	fromwire(cursor, max, fromwire_pad_arr, num);
-}
-
 /* memsetting pubkeys doesn't work */
 static void set_pubkey(struct pubkey *key)
 {