[3.7] bpo-36254: Fix invalid uses of %d in format strings in C. (GH-12264). (GH-12322)

(cherry picked from commit d53fe5f407ff4b529628b01a1bcbf21a6aad5c3a)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
diff --git a/Modules/_io/winconsoleio.c b/Modules/_io/winconsoleio.c
index c11c1e0..bf5b10b 100644
--- a/Modules/_io/winconsoleio.c
+++ b/Modules/_io/winconsoleio.c
@@ -724,7 +724,7 @@
 
     if (u8n) {
         PyErr_Format(PyExc_SystemError,
-            "Buffer had room for %d bytes but %d bytes required",
+            "Buffer had room for %zd bytes but %u bytes required",
             len, u8n);
         return -1;
     }