net: tftp: use correct printf codes

When printing unsigned numbers use %u.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/net/tftp.c b/net/tftp.c
index 0240189..585eb6e 100644
--- a/net/tftp.c
+++ b/net/tftp.c
@@ -223,7 +223,7 @@
 
 	tosend = min(net_boot_file_size - offset, tosend);
 	(void)memcpy(dst, (void *)(image_save_addr + offset), tosend);
-	debug("%s: block=%d, offset=%ld, len=%d, tosend=%ld\n", __func__,
+	debug("%s: block=%u, offset=%lu, len=%u, tosend=%lu\n", __func__,
 	      block, offset, len, tosend);
 	return tosend;
 }