sched: clean up is_migration_thread()

clean up is_migration_thread() and turn it into an inline function.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index 2c6295b..7ef66bd 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -75,12 +75,6 @@
 	return (unsigned long long)jiffies * (1000000000 / HZ);
 }
 
-#ifdef CONFIG_SMP
-#define is_migration_thread(p, rq) ((p) == (rq)->migration_thread)
-#else
-#define is_migration_thread(p, rq) 0
-#endif
-
 /*
  * Convert user-nice values [ -20 ... 0 ... 19 ]
  * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
@@ -371,6 +365,15 @@
 #endif
 }
 
+static inline int is_migration_thread(struct task_struct *p, struct rq *rq)
+{
+#ifdef CONFIG_SMP
+	return p == rq->migration_thread;
+#else
+	return 0;
+#endif
+}
+
 /*
  * Update the per-runqueue clock, as finegrained as the platform can give
  * us, but without assuming monotonicity, etc.: