writeback: remove writeback_control.more_io

When wbc.more_io was first introduced, it indicates whether there are
at least one superblock whose s_more_io contains more IO work. Now with
the per-bdi writeback, it can be replaced with a simple b_more_io test.

Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index 4e249b9..b2cfac5 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -101,7 +101,6 @@
 		__field(int, for_background)
 		__field(int, for_reclaim)
 		__field(int, range_cyclic)
-		__field(int, more_io)
 		__field(unsigned long, older_than_this)
 		__field(long, range_start)
 		__field(long, range_end)
@@ -116,7 +115,6 @@
 		__entry->for_background	= wbc->for_background;
 		__entry->for_reclaim	= wbc->for_reclaim;
 		__entry->range_cyclic	= wbc->range_cyclic;
-		__entry->more_io	= wbc->more_io;
 		__entry->older_than_this = wbc->older_than_this ?
 						*wbc->older_than_this : 0;
 		__entry->range_start	= (long)wbc->range_start;
@@ -124,7 +122,7 @@
 	),
 
 	TP_printk("bdi %s: towrt=%ld skip=%ld mode=%d kupd=%d "
-		"bgrd=%d reclm=%d cyclic=%d more=%d older=0x%lx "
+		"bgrd=%d reclm=%d cyclic=%d older=0x%lx "
 		"start=0x%lx end=0x%lx",
 		__entry->name,
 		__entry->nr_to_write,
@@ -134,7 +132,6 @@
 		__entry->for_background,
 		__entry->for_reclaim,
 		__entry->range_cyclic,
-		__entry->more_io,
 		__entry->older_than_this,
 		__entry->range_start,
 		__entry->range_end)