Fix build error when XLOG is enabled

(cherrypick of 79a49c9857f3949fc13373eeb179f27b6ecdca81.)

Change-Id: I7bb44fd1fe3ef2ddfc115247f328eccfceeb5352
Signed-off-by: Patrick Tjin <pattjin@google.com>
diff --git a/libc/dns/resolv/res_cache.c b/libc/dns/resolv/res_cache.c
index 15d04c2..c431835 100644
--- a/libc/dns/resolv/res_cache.c
+++ b/libc/dns/resolv/res_cache.c
@@ -1090,7 +1090,7 @@
         XLOG("ns_parserr failed. %s\n", strerror(errno));
     }
 
-    XLOG("TTL = %d\n", result);
+    XLOG("TTL = %lu\n", result);
 
     return result;
 }