fix format string

Index: iodev/network/netutil.cc
--- iodev/network/netutil.cc.orig
+++ iodev/network/netutil.cc
@@ -1671,11 +1671,11 @@ void vnet_server_c::ftp_list_directory(tcp_conn_t *tcp
                 strftime(tmptime, 20, "%b %d %H:%M", localtime(&st.st_mtime));
               }
               if (S_ISDIR(st.st_mode)) {
-                sprintf(linebuf, "drwxrwxr-x 1 ftp ftp %ld %s %s%c%c", st.st_size,
-                        tmptime, dent->d_name, 13, 10);
+                sprintf(linebuf, "drwxrwxr-x 1 ftp ftp %lld %s %s%c%c",
+			(long long) st.st_size, tmptime, dent->d_name, 13, 10);
               } else {
-                sprintf(linebuf, "-rw-rw-r-- 1 ftp ftp %ld %s %s%c%c", st.st_size,
-                        tmptime, dent->d_name, 13, 10);
+                sprintf(linebuf, "-rw-rw-r-- 1 ftp ftp %lld %s %s%c%c",
+			(long long)st.st_size, tmptime, dent->d_name, 13, 10);
               }
             }
           } else {
