avcodec/prosumer: Reduce lut size

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/prosumer.c

@@ -38,7 +38,7 @@ typedef struct ProSumerContext {
 
     unsigned stride;
     unsigned size;
-    uint32_t lut[0x10000];
+    uint32_t lut[0x2000];
     uint8_t *initial_line;
     uint8_t *decbuffer;
 } ProSumerContext;