Avoid logging errors for non-existing devices

Index: seatd/seat.c
--- seatd/seat.c.orig
+++ seatd/seat.c
@@ -383,7 +383,9 @@ struct seat_device *seat_open_device(struct client *cl
 
 	int fd = open(sanitized_path, O_RDWR | O_NOCTTY | O_NOFOLLOW | O_CLOEXEC | O_NONBLOCK);
 	if (fd == -1) {
-		log_errorf("Could not open file: %s", strerror(errno));
+		if (errno != ENXIO) {
+			log_errorf("Could not open file: %s", strerror(errno));
+		}
 		return NULL;
 	}
 
