sched: fix style of swap() macro in kernel/sched_fair.c

fix style of swap() macro in kernel/sched_fair.c.

( this macro should eventually move to a general header, as ext3 uses
  a similar construct too. )

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 9971831..01859f6 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1025,7 +1025,7 @@
 	}
 }
 
-#define swap(a,b) do { typeof(a) tmp = (a); (a) = (b); (b) = tmp; } while (0)
+#define swap(a, b) do { typeof(a) tmp = (a); (a) = (b); (b) = tmp; } while (0)
 
 /*
  * Share the fairness runtime between parent and child, thus the