fate: make smjpeg a demux test

These codecs are covered elsewhere so make this a pure demux test.
Also rename it accordingly.
Signed-off-by: Mans Rullgard <mans@mansr.com>

tests/fate/demux.mak

@@ -58,8 +58,8 @@ fate-redcode-demux: CMD = framecrc -i $(SAMPLES)/r3d/4MB-sample.r3d -vcodec copy
 FATE_AVCONV += fate-siff
 fate-siff: CMD = framecrc -i $(SAMPLES)/SIFF/INTRO_B.VB -t 3 -pix_fmt rgb24
 
-FATE_AVCONV += fate-smjpeg
-fate-smjpeg: CMD = framecrc -i $(SAMPLES)/smjpeg/scenwin.mjpg -vcodec copy
+FATE_AVCONV += fate-smjpeg-demux
+fate-smjpeg-demux: CMD = framecrc -i $(SAMPLES)/smjpeg/scenwin.mjpg -c copy
 
 FATE_AVCONV += fate-westwood-aud
 fate-westwood-aud: CMD = framecrc -i $(SAMPLES)/westwood-aud/excellent.aud -c copy