[PVR] Fix CPVRDirectory::GetDirectory not to return false in case PVR is not yet (compeletely started).

[ksooo]

Fixes log spam on Kodi startup:

21:49:43 T:2984   ERROR: XFILE::CDirectory::GetDirectory - Error getting pvr://channels/tv/*?view=lastplayed
21:49:43 T:2984   ERROR: XFILE::CDirectory::GetDirectory - Error getting pvr://recordings/tv/active?view=flat
21:49:43 T:2984   ERROR: XFILE::CDirectory::GetDirectory - Error getting pvr://channels/radio/*?view=lastplayed
21:49:43 T:2984   ERROR: XFILE::CDirectory::GetDirectory - Error getting pvr://recordings/radio/active?view=flat

GetDirectory return value semantics is "successfully handed" which can be different from "successfully read directory content". ;-)

This is actually a regression I introduced while working on the new pvr home screen widgets.

@Jalle19 mind taking a look at the code change.

[mention-bot]

@ksooo, thanks for your PR! By analyzing the history of the files in this pull request, we identified @opdenkamp, @AlwinEsch and @xhaggi to be potential reviewers.

[xhaggi]

looks good

[ksooo]

Jenkins build this please