MAINTAINERS: add Miaohe Lin as a memory-failure reviewer

I have been focusing on mm for the past two years.  e.g.  fixing bugs,
cleaning up the code and reviewing.  I would like to help maintainers and
people working on memory-failure by reviewing their work.

Let me be Cc'd on patches related to memory-failure.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Acked-by: Naoya Horiguchi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: MiaoheLin

MAINTAINERS

@@ -9132,6 +9132,7 @@ F:	drivers/media/platform/st/sti/hva
 
 HWPOISON MEMORY FAILURE HANDLING
 M:	Naoya Horiguchi <[email protected]>
+R:	Miaohe Lin <[email protected]>
 L:	[email protected]
 S:	Maintained
 F:	mm/hwpoison-inject.c