perf counters: clean up state transitions

Impact: cleanup

Introduce a proper enum for the 3 states of a counter:

	PERF_COUNTER_STATE_OFF		= -1
	PERF_COUNTER_STATE_INACTIVE	=  0
	PERF_COUNTER_STATE_ACTIVE	=  1

and rename counter->active to counter->state and propagate the
changes everywhere.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 97d86c2..8cb095f 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -128,6 +128,15 @@
 };
 
 /**
+ * enum perf_counter_active_state - the states of a counter
+ */
+enum perf_counter_active_state {
+	PERF_COUNTER_STATE_OFF		= -1,
+	PERF_COUNTER_STATE_INACTIVE	=  0,
+	PERF_COUNTER_STATE_ACTIVE	=  1,
+};
+
+/**
  * struct perf_counter - performance counter kernel representation:
  */
 struct perf_counter {
@@ -136,7 +145,7 @@
 	struct perf_counter		*group_leader;
 	const struct hw_perf_counter_ops *hw_ops;
 
-	int				active;
+	enum perf_counter_active_state	state;
 #if BITS_PER_LONG == 64
 	atomic64_t			count;
 #else