CHICAGO – “The FP,” playing in midnight shows this weekend at Music Box and in various arthouse theaters around the country, is a hard movie to put your finger on. Is it just bad like “Birdemic” or “The Room” or is it something “trying” to be bad? Is it a spoof of bad movies or just a bad movie? Does it matter? Either way, “The FP” works for its audience, a rowdy crowd of midnight movie fans willing to put up with over-the-top silliness, bad performances, and general lunacy. It’s essentially an extended short film that doesn’t even justify its short running time but audiences on its wavelength will eat it up.