3752 want more verifiable dbuf user eviction
Submitted by:   Justin Gibbs <justing@spectralogic.com>
Submitted by:   Will Andrews <willa@spectralogic.com>

@@ -33,10 +33,13 @@
 
 #ifdef  __cplusplus
 extern "C" {
 #endif
 
+#ifndef _KERNEL
+#include <stddef.h>
+#endif
 #include <sys/note.h>
 #include <sys/types.h>
 #include <sys/t_lock.h>
 #include <sys/atomic.h>
 #include <sys/sysmacros.h>