avcodec/x86/sbrdsp: Fix using uninitialized upper 32bit of noise

Fixes crash
Fixes: flicker-1.scout3d21443372922.28.m4a
Found-by: Dale Curtis <dalecurtis@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/x86/sbrdsp.asm

@@ -382,6 +382,7 @@ apply_noise_main:
 %else
 %define count m_maxq
 %endif
+    movsxdifnidn    noiseq, noised
     dec    noiseq
     shl    count, 2
 %ifdef PIC