Correctly print time_t.

Index: src/rrd_lastupdate.c
--- src/rrd_lastupdate.c.orig
+++ src/rrd_lastupdate.c
@@ -77,11 +77,7 @@ int rrd_lastupdate (int argc, char **argv)
         printf(" %s", ds_names[i]);
     printf ("\n\n");
 
-#if defined _WIN32 && SIZEOF_TIME_T == 8    /* in case of __MINGW64__, _WIN64 and _MSC_VER >= 1400 (ifndef _USE_32BIT_TIME_T) */
-    printf ("%10llu:", last_update);        /* argument 2 has type 'time_t {aka long long int} */
-#else
-    printf ("%10lu:", last_update);
-#endif
+    printf ("%10llu:", (long long)last_update);        /* argument 2 has type 'time_t {aka long long int} */
     for (i = 0; i < ds_count; i++) {
         printf(" %s", last_ds[i]);
         free(last_ds[i]);