hsm: give it its own log, so it has unique prefix.

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

lightningd/hsm_control.c

@@ -40,6 +40,7 @@ void hsm_init(struct lightningd *ld, bool newdir)
 	if (ld->hsm_fd < 0)
 		err(1, "Could not subd hsm");
 
+	ld->hsm_log = new_log(ld, ld->log_book, "hsmd:");
 	if (newdir)
 		create = true;
 	else

lightningd/lightningd.h

@@ -107,6 +107,7 @@ struct lightningd {
 
 	/* Bearer of all my secrets. */
 	int hsm_fd;
+	struct log *hsm_log;
 
 	/* Daemon looking after peers during init / before channel. */
 	struct subd *gossip;