MAINTAINERS: add Chris and Kairui as the swap maintainer

We have been collaborating on a systematic effort to clean up and improve
the Linux swap system, and might as well take responsibility for it.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Chris Li <[email protected]>
Acked-by: Kairui Song <[email protected]>
Acked-by: Barry Song <[email protected]>
Acked-by: Baoquan He <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kemeng Shi <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nhat Pham <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: Chris Li

MAINTAINERS

@@ -16498,12 +16498,12 @@ F:	mm/secretmem.c
 
 MEMORY MANAGEMENT - SWAP
 M:	Andrew Morton <[email protected]>
+M:	Chris Li <[email protected]>
+M:	Kairui Song <[email protected]>
 R:	Kemeng Shi <[email protected]>
-R:	Kairui Song <[email protected]>
 R:	Nhat Pham <[email protected]>
 R:	Baoquan He <[email protected]>
 R:	Barry Song <[email protected]>
-R:	Chris Li <[email protected]>
 L:	[email protected]
 S:	Maintained
 F:	Documentation/mm/swap-table.rst