[PATCH] swap: update swapfile i_sem comment

Update swap extents comment: nowadays we guard with S_SWAPFILE not i_sem.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 60cd24a..9f46d83 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -926,7 +926,7 @@
  * requirements, they are simply tossed out - we will never use those blocks
  * for swapping.
  *
- * For S_ISREG swapfiles we hold i_sem across the life of the swapon.  This
+ * For S_ISREG swapfiles we set S_SWAPFILE across the life of the swapon.  This
  * prevents root from shooting her foot off by ftruncating an in-use swapfile,
  * which will scribble on the fs.
  *