qcow2.h: add missing include

qcow2.h: add missing include

qcow2.h depends on block_int.h. Compilation isn't broken currently only
due to block_int.h always included before qcow2.h. Though, it seems
better to directly include block_int.h in qcow2.h.

Signed-off-by: Vladimir Sementsov-Ogievskiy <[email protected]>
Reviewed-by: Alberto Garcia <[email protected]>
Reviewed-by: Max Reitz <[email protected]>
Message-id: 20190506142741[email protected]
Signed-off-by: Max Reitz <[email protected]>