cleanup: remove redundant search for hovered VFO

[ericek111]

The ImGui::IsMouseHoveringRect check is done every frame for drawing the tooltip when hovering above a VFO. It's already done a few lines earlier at the beginning of processInputs, so there's no need to do it again.

I'm also debugging the ImGui::GetIO().KeyCtrl thing. It seems to be false when I start SDR++, then stays false as I hold Ctrl and becomes true upon releasing it (reversing the entire logic).