FATE: add test for xWMA demuxer.

(Does not attempt to decode percetual audio data inside.)
Code coverage: libavformat/xwma.c: 3% -> 75%

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

tests/fate/demux.mak

@@ -90,3 +90,6 @@ fate-wtv-demux: CMD = framecrc -i $(SAMPLES)/wtv/law-and-order-partial.wtv -vcod
 
 FATE_TESTS += fate-xmv-demux
 fate-xmv-demux: CMD = framecrc -i $(SAMPLES)/xmv/logos1p.fmv -vcodec copy -acodec copy
+
+FATE_TESTS += fate-xwma-demux
+fate-xwma-demux: CMD = crc -i $(SAMPLES)/xwma/ergon.xwma -acodec copy

tests/ref/fate/xwma-demux

+CRC=0x2ac2159e