Block nodes that do not allow resizing should not share BLK_PERM_RESIZE.
It does not matter whether they are the first non-filter in their chain
or not.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200218103454.296704-3-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>