This change fixes a small but user-visible state bug in ziptuner.c: when switching from a search menu into favorites, the code could reuse previtem from the earlier search context. The update explicitly clears previtem before favorites handling, then sets it only from favnum when a favorite should actually be played. In practice, favorites navigation and autoplay should now behave consistently instead of inheriting the wrong prior selection.

Reset the previous selection before loading favorites so search state doesn't leak into favorites playback. - zhengqunkoo/ziptuner