Fix implementation of the DECLARE_WORK() macro in the LinuxKPI to fully

initialize the declared work structure and not only the function callback
pointer.

MFC after:		1 week
Sponsored by:		Mellanox Technologies

sys/compat/linuxkpi/common/include/linux/workqueue.h

@@ -72,8 +72,13 @@ struct work_struct {
 	atomic_t state;
 };
 
-#define	DECLARE_WORK(name, fn) \
-	struct work_struct name = { .func = (fn) }
+#define	DECLARE_WORK(name, fn)						\
+	struct work_struct name;					\
+	static void name##_init(void *arg)				\
+	{								\
+		INIT_WORK(&name, fn);					\
+	}								\
+	SYSINIT(name, SI_SUB_LOCK, SI_ORDER_SECOND, name##_init, NULL)
 
 struct delayed_work {
 	struct work_struct work;