media: dvb: Fix parsing of SDMX results

When playing from memory, it may happen that demux thread
is stalled while parsing SDMX results due to PULL mode.
While thread is stalled it is possible that user asked to
add new filter and therefore the SDMX filter count increases.

When thread gets back from stalling, it may parse additional
filters result even-though they were not processed by SDMX yet,
hence parsing un-initialized data.

Change-Id: Idb9430ec07f5869585ed1ae9ab3d43c4d31ff4d2
Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>