Remove tal_len, use tal_count() or tal_bytelen().

tal_count() is used where there's a type, even if it's char or u8, and
tal_bytelen() is going to replace tal_len() for clarity: it's only needed
where a pointer is void.

We shim tal_bytelen() for now.

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

lightningd/log_status.c

@@ -14,7 +14,7 @@ bool log_status_msg(struct log *log, const u8 *msg)
 		}
 	} else if (fromwire_status_io(msg, msg, &level, &who, &data)) {
 		if (level == LOG_IO_IN || level == LOG_IO_OUT) {
-			log_io(log, level, who, data, tal_len(data));
+			log_io(log, level, who, data, tal_count(data));
 			return true;
 		}
 	}