ublk: add a MAINTAINERS entry

Make get_maintainers.pl work for ublk.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220721130916.1869719-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

MAINTAINERS

@@ -20415,6 +20415,13 @@ F:	Documentation/filesystems/ubifs-authentication.rst
 F:	Documentation/filesystems/ubifs.rst
 F:	fs/ubifs/
 
+UBLK USERSPACE BLOCK DRIVER
+M:	Ming Lei <ming.lei@redhat.com>
+L:	linux-block@vger.kernel.org
+S:	Maintained
+F:	drivers/block/ublk_drv.c
+F:	include/uapi/linux/ublk_cmd.h
+
 UCLINUX (M68KNOMMU AND COLDFIRE)
 M:	Greg Ungerer <gerg@linux-m68k.org>
 L:	linux-m68k@lists.linux-m68k.org