freezer: remove should_send_signal() and update frozen()

should_send_signal() is only used in freezer.c.  Exporting them only
increases chance of abuse.  Open code the two users and remove it.

Update frozen() to return bool.
Signed-off-by: Tejun Heo <tj@kernel.org>

include/linux/freezer.h

@@ -15,7 +15,7 @@ extern bool pm_nosig_freezing;		/* PM nosig freezing in effect */
 /*
  * Check if a process has been frozen
  */
-static inline int frozen(struct task_struct *p)
+static inline bool frozen(struct task_struct *p)
 {
 	return p->flags & PF_FROZEN;
 }
@@ -32,11 +32,6 @@ static inline bool freezing(struct task_struct *p)
 	return freezing_slow_path(p);
 }
 
-static inline bool should_send_signal(struct task_struct *p)
-{
-	return !(p->flags & PF_FREEZER_NOSIG);
-}
-
 /* Takes and releases task alloc lock using task_lock() */
 extern void __thaw_task(struct task_struct *t);
 
@@ -166,7 +161,7 @@ static inline void set_freezable_with_signal(void)
 	__retval;							\
 })
 #else /* !CONFIG_FREEZER */
-static inline int frozen(struct task_struct *p) { return 0; }
+static inline bool frozen(struct task_struct *p) { return false; }
 static inline bool freezing(struct task_struct *p) { return false; }
 
 static inline bool __refrigerator(bool check_kthr_stop) { return false; }

kernel/freezer.c

@@ -132,7 +132,7 @@ bool freeze_task(struct task_struct *p, bool sig_only)
 		return false;
 	}
 
-	if (should_send_signal(p)) {
+	if (!(p->flags & PF_FREEZER_NOSIG)) {
 		fake_signal_wake_up(p);
 		/*
 		 * fake_signal_wake_up() goes through p's scheduler