[pvr] cosmetics: renames m_selectedItemPath to m_selectedItemPaths to reflect it's a map
[pvr] fix selecting current playing item

As m_selectedItemPaths is a map we need to check if the corresponding map value is empty instead of the whole map.
Merge pull request #5325 from xhaggi/pvr-fix-selecting-playing-item

[pvr] fix selecting playing item in PVR windows