irdeto: Fix EMM filters.

What this commit does:
  - Allow shared to hex serial only for betacrypt. This allows one more
    free filter slot for Irdeto.
  - Skip not initialised providers. They always have first and third byte 0x00.
  - Improve exit conditions from provider loop. Previous patch could result
    in memory overwrite.
  - Only display "could not start all emm filters" if we break out of the
    provider loop. Previously it would display this message even if we
    haven't skipped emm filters.

Patch by malakudi posted in ticket #3198.

git-svn-id: http://streamboard.de.vu/svn/oscam/trunk@8458 4b0bc96b-bc66-0410-9d44-ebda105a78c1