mm/page-writeback: fix non-kernel-doc function comments

Remove leading /** from non-kernel-doc function comments to prevent
kernel-doc warnings.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 20890d8..7262aac 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -397,7 +397,7 @@
 	return x + 1;	/* Ensure that we never return 0 */
 }
 
-/**
+/*
  * global_dirty_limits - background-writeback and dirty-throttling thresholds
  *
  * Calculate the dirty thresholds based on sysctl parameters
@@ -440,7 +440,7 @@
 	*pdirty = dirty;
 }
 
-/**
+/*
  * bdi_dirty_limit - @bdi's share of dirty throttling threshold
  *
  * Allocate high/low dirty limits to fast/slow devices, in order to prevent