state: make bitcoin_commit() take a non-const peer.

We have to sign the commit at this stage, so easiest if peer isn't const
so we can sign it in-place.

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

state.h

@@ -369,8 +369,7 @@ const struct bitcoin_tx *bitcoin_steal(const tal_t *ctx,
 				       struct bitcoin_event *btc);
 
 /* Create our commit tx */
-const struct bitcoin_tx *bitcoin_commit(const tal_t *ctx,
-					const struct peer *peer);
+const struct bitcoin_tx *bitcoin_commit(const tal_t *ctx, struct peer *peer);
 
 /* Create a HTLC refund collection */
 const struct bitcoin_tx *bitcoin_htlc_timeout(const tal_t *ctx,

test/test_state_coverage.c

@@ -894,8 +894,7 @@ const struct bitcoin_tx *bitcoin_steal(const tal_t *ctx,
 	return bitcoin_tx("steal");
 }
 
-const struct bitcoin_tx *bitcoin_commit(const tal_t *ctx,
-					const struct peer *peer)
+const struct bitcoin_tx *bitcoin_commit(const tal_t *ctx, struct peer *peer)
 {
 	return bitcoin_tx("our commit");
 }