The function is replaced by dvbpsi_decoder_chain_get() that looksup a
decoder by its table_id and extension in a linked list.

Only when dvbpsi_decoder_t::pf_del() is not available dvbpsi_decoder_delete() is called
from this function.

This example application has been superseeded by dvbinfo example.

Directly accessing dvbpsi_t::p_decoder is no longer safe, since this holds
a linked list (aka chain) of decoders now.

The interface argument for udp_open was never passed on to the appropriate function.

This API deprecates the dvbpsi_demux* API.

(cherry picked from commit d1d2e934)
Signed-off-by: Jean-Paul Saman <jpsaman@videolan.org>

Remove duplicated check for descriptor tags in GetDescriptorName()