Prevent double notification for frame done in external frame usage

[tszumski]

Skip notify if ext_frame is used and derive is false (input_fmt != transport_fmt).
In this case, the frame done notification is not needed since the notification is already done after convert callback.
This is to avoid double notification(and double free) for the same frame.
Fixes #1147

[DawidWesierski4]

LGTM

[Sakoram]

I think this solution is insufficient. As a user I expect notify_frame_done to be called each time the buffer ownership returns to me.
Currently I see a scenario in which it is not the case:
ext_frame, but external converter is used. I guess we need to add a call to notify_frame_done in tx_st20p_convert_put_frame()

There are possible more such scenarios, please check if the user is informed in each.

[tszumski]

I think this solution is insufficient. As a user I expect notify_frame_done to be called each time the buffer ownership returns to me. Currently I see a scenario in which it is not the case: ext_frame, but external converter is used. I guess we need to add a call to notify_frame_done in tx_st20p_convert_put_frame()

There are possible more such scenarios, please check if the user is informed in each.

Thanks, good catch, fixed in fd0a79b