pvr: fix seek for recordings

[FernetMenta]

there seems to be no need to overwrite total and current playing time for recordings. some other things i was struggling with:

• GetStartTime is misleading. it actually is the current playing time of a live stream and zero for recordings
• recording.GetDuration returns minutes. i am not sure if this is used in other places and didn't want to change it

[opdenkamp]

yeah noticed it too when I was working at that code last week. can't remember why I didn't change the name (think it was because it's named GetStartTime() in other places in the code too). pretty sure I documented the meaning though.

it's in minutes because the pvr backends usually use minutes for duration instead of seconds. but since xbmc is using seconds everywhere else, I'll change it and convert it to minutes on the pvr interface

[opdenkamp]

hmm, now that I look into the code, I see that it's mixing up minutes and seconds on the interface too...

[opdenkamp]

changed it in 197e35b so it only uses seconds now.

[FernetMenta]

yep, i really did appreciate your comment in the code!