MAINTAINERS: add myself as vmalloc co-maintainer

I have been working on the vmalloc code for several years, contributing to
improvements and fixes.  Add myself as co-maintainer ("M") alongside
Andrew Morton.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Uladzislau Rezki (Sony) <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Acked-by: Lorenzo Stoakes <[email protected]>
Acked-by: Baoquan He <[email protected]>
Cc: Christop Hellwig <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: urezki

MAINTAINERS

@@ -25906,7 +25906,7 @@ F:	tools/testing/vsock/
 
 VMALLOC
 M:	Andrew Morton <[email protected]>
-R:	Uladzislau Rezki <[email protected]>
+M:	Uladzislau Rezki <[email protected]>
 L:	[email protected]
 S:	Maintained
 W:	http://www.linux-mm.org