mkfs-util: Always use "default" usage type for ext filesystems

If no usage type is explicitly specified, ext will choose one based
on the filesystem size. Let's override this and always use the
"default" usage type so that we can create filesystems that are
initially small but might grow later without opting in to the "small"
usage type.

src/shared/mkfs-util.c

@@ -361,6 +361,7 @@ int make_filesystem(
                                 "-m", "0",
                                 "-E", discard ? "discard,lazy_itable_init=1" : "nodiscard,lazy_itable_init=1",
                                 "-b", "4096",
+                                "-T", "default",
                                 node);
                 if (!argv)
                         return log_oom();
@@ -378,6 +379,7 @@ int make_filesystem(
                                 "-m", "0",
                                 "-E", discard ? "discard,lazy_itable_init=1" : "nodiscard,lazy_itable_init=1",
                                 "-b", "4096",
+                                "-T", "default",
                                 node);
 
                 if (root && strv_extend_strv(&argv, STRV_MAKE("-d", root), false) < 0)