Trivial prototype change

Change the name of the argument of wake_with from "Pred" to "Action".
This argument is a function to run, *not* a predicate (it's not supposed
to return a boolean value), so it doesn't make sense to call it Pred.

The implementation of wake_with already used the name "Action" - this
patch fixes the prototype too.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>

include/sched.hh

@@ -202,8 +202,8 @@ public:
     template <class Pred>
     static void wait_until(mutex_t* mtx, Pred pred);
     void wake();
-    template <class Pred>
-    inline void wake_with(Pred pred);
+    template <class Action>
+    inline void wake_with(Action action);
     static void sleep_until(s64 abstime);
     static void yield();
     static void exit() __attribute__((__noreturn__));