MAINTAINERS: Add qemu-progress to the block layer

util/qemu-progress.c is currently unmaintained. The only user of its
functionality is qemu-img, so it effectively is part of the block layer.
Suggested-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Message-id: 20170428165517.30341-1-mreitz@redhat.com
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>

MAINTAINERS

@@ -1170,6 +1170,7 @@ F: include/block/
 F: qemu-img*
 F: qemu-io*
 F: tests/qemu-iotests/
+F: util/qemu-progress.c
 T: git git://repo.or.cz/qemu/kevin.git block
 
 Block I/O path