[pvr] search start time/end time were swapped
[pvr] the channel used for updating channel spinner wasn't correct
[pvr] clear the channel spinner in the guide search before filling
[pvr] the current channel wasn't set in the channel spinner when filled in the guide search dialog
Merge pull request #4732 from jmarshallnz/pvr_fixes

PVR: A couple of fixes in guide search dialog