GCC 9.1 complains about this wrong type used in the format string, fix
this to make the compiler happy.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
--- /dev/null
+--- a/urngd.c
++++ b/urngd.c
+@@ -114,7 +114,7 @@ static size_t gather_entropy(struct urng
+
+ ret = write_entropy(u, buf, sizeof(buf), ENTROPYBYTES);
+ if (sizeof(buf) != ret) {
+- ERROR("injected %lub of entropy, less then %db expected\n",
++ ERROR("injected %zub of entropy, less then %db expected\n",
+ ret, sizeof(buf));
+ } else {
+ ret = sizeof(buf);