block: Pass parent_is_format to .inherit_options()

block: Pass parent_is_format to .inherit_options()

We plan to unify the generic .inherit_options() functions.  The
resulting common function will need to decide whether to force-enable
format probing, force-disable it, or leave it as-is.  To make this
decision, it will need to know whether the parent node is a format node
or not (because we never want format probing if the parent is a format
node already (except for the backing chain)).

Signed-off-by: Max Reitz <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Message-Id: <20200513110544[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>