test: include headers for struct statfs

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>

src/test/mon/test_mon_workloadgen.cc

@@ -11,6 +11,16 @@
  * Foundation.  See file COPYING.
  * 
  */
+#include "acconfig.h"
+
+#ifdef HAVE_SYS_MOUNT_H
+#include <sys/mount.h>
+#endif
+
+#ifdef HAVE_SYS_PARAM_H
+#include <sys/param.h>
+#endif
+
 #include <iostream>
 #include <string>
 #include <map>