console-server: Fix printf() format string for discovered handlers

GCC reports the following on ARM:

```
../../../../../../workspace/sources/obmc-console/console-server.c: In function 'handlers_init':
../../../../../../workspace/sources/obmc-console/console-server.c:549:19: error: format '%ld' expects argument of type 'long int', but argument 2 has type 'size_t' {aka 'unsigned int'} [-Werror=format=]
  549 |         printf("%ld handler type%s\n", n_types, n_types == 1 ? "" : "s");
      |                 ~~^                    ~~~~~~~
      |                   |                    |
      |                   long int             size_t {aka unsigned int}
      |                 %d
```

Change-Id: Ib40f2e0576588d8dbd6fd38c4e969a1749c18538
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/console-server.c b/console-server.c
index 4ff3a4e..d71c63a 100644
--- a/console-server.c
+++ b/console-server.c
@@ -546,7 +546,7 @@
 		err(EXIT_FAILURE, "malloc(handlers)");
 	}
 
-	printf("%ld handler type%s\n", n_types, n_types == 1 ? "" : "s");
+	printf("%zu handler type%s\n", n_types, n_types == 1 ? "" : "s");
 
 	for (i = 0; i < n_types; i++) {
 		const struct handler_type *type = &__start_handlers[i];