fix DST DVB-S get_frequency

 - fixes a bug that caused the returned frequency to wrong
Signed-off-by: NTom Hughes <tom@compton.nu>
Signed-off-by: NManu Abraham <manu@linuxtv.org>
Signed-off-by: NMichael Krufky <mkrufky@linuxtv.org>
Cc: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>