qapi/block-core: Drop drive-backup's "Any other error" documentation

We've always been rather lax about documenting errors.  Many "Errors"
sections are obviously not exhaustive.  Only drive-backup is explicit
about this: "Any other error returns a GenericError".

Not useful.  Drop.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240911132459.2548063-3-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
1 file changed