mm/swap.c: not necessary to export __pagevec_lru_add()

__pagevec_lru_add() is only used in mm directory now.

Remove the export symbol.
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200126011436.22979-1-richardw.yang@linux.intel.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/swap.c

@@ -986,7 +986,6 @@ void __pagevec_lru_add(struct pagevec *pvec)
 {
 	pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, NULL);
 }
-EXPORT_SYMBOL(__pagevec_lru_add);
 
 /**
  * pagevec_lookup_entries - gang pagecache lookup