Fix format string warnings

Also fixes bug #768199:

https://bugzilla.gnome.org/show_bug.cgi?id=768199
diff --git a/testlimits.c b/testlimits.c
index 577f593..68c94db 100644
--- a/testlimits.c
+++ b/testlimits.c
@@ -1284,13 +1284,14 @@
         if (fail)
             res = 0;
         else {
-            fprintf(stderr, "Failed to parse '%s' %lu\n", filename, limit);
+            fprintf(stderr, "Failed to parse '%s' %lu\n", filename,
+                    (unsigned long) limit);
             res = 1;
         }
     } else {
         if (fail) {
             fprintf(stderr, "Failed to get failure for '%s' %lu\n",
-                    filename, limit);
+                    filename, (unsigned long) limit);
             res = 1;
         } else
             res = 0;
@@ -1339,7 +1340,7 @@
                         filename, crazy_indx);
             else
                 fprintf(stderr, "Failed to parse '%s' %lu\n",
-                        filename, limit);
+                        filename, (unsigned long) limit);
             res = 1;
         }
     } else {
@@ -1349,7 +1350,7 @@
                         filename, crazy_indx);
             else
                 fprintf(stderr, "Failed to get failure for '%s' %lu\n",
-                        filename, limit);
+                        filename, (unsigned long) limit);
             res = 1;
         } else
             res = 0;