Issue #9611: remove useless and dangerous explicit conversion to size_t
diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 2e5d7ac..f96f2e2 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -530,7 +530,7 @@
             len = INT_MAX;
         n = read(self->fd, pbuf.buf, (int)len);
 #else
-        n = read(self->fd, pbuf.buf, (size_t)len);
+        n = read(self->fd, pbuf.buf, len);
 #endif
         Py_END_ALLOW_THREADS
     } else
@@ -716,7 +716,7 @@
             len = INT_MAX;
         n = write(self->fd, pbuf.buf, (int)len);
 #else
-        n = write(self->fd, pbuf.buf, (size_t)len);
+        n = write(self->fd, pbuf.buf, len);
 #endif
         Py_END_ALLOW_THREADS
     } else