MAINTAINERS: update ublk driver maintainer email

Update the ublk userspace block driver maintainer email address
from [email protected] to [email protected] as the original
email will become invalid.

Signed-off-by: Ming Lei <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

Author: ming1

MAINTAINERS

@@ -26992,7 +26992,7 @@ F:	Documentation/filesystems/ubifs.rst
 F:	fs/ubifs/
 
 UBLK USERSPACE BLOCK DRIVER
-M:	Ming Lei <ming.lei@redhat.com>
+M:	Ming Lei <tom.leiming@gmail.com>
 L:	[email protected]
 S:	Maintained
 F:	Documentation/block/ublk.rst