vmstat: fix dirty threshold ordering

The nr_dirty_[background_]threshold fields are misplaced before the
numa_* fields, and users will read strange values.

This is the right order. Before patch, nr_dirty_background_threshold
will read as 0 (the value from numa_miss).

numa_hit 128501
numa_miss 0
numa_foreign 0
numa_interleave 7388
numa_local 128501
numa_other 0
nr_dirty_threshold 144291
nr_dirty_background_threshold 72145

Signed-off-by: Wu Fengguang <[e-mail]>
Cc: Michael Rubin <[e-mail]>
Reviewed-by: KOSAKI Motohiro <[e-mail]>
Reviewed-by: Minchan Kim <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

mm/vmstat.c

···
 	"nr_shmem",
 	"nr_dirtied",
 	"nr_written",
-	"nr_dirty_threshold",
-	"nr_dirty_background_threshold",
 
 #ifdef CONFIG_NUMA
 	"numa_hit",
···
 	"numa_local",
 	"numa_other",
 #endif
+	"nr_dirty_threshold",
+	"nr_dirty_background_threshold",
 
 #ifdef CONFIG_VM_EVENT_COUNTERS
 	"pgpgin",