ac3: Do not clash with normal AVERROR

The parsing function return AVERROR and AAC_AC3_PARSE_ERROR values,
make sure they are not misunderstood.

libavcodec/aac_ac3_parser.h

@@ -28,13 +28,13 @@
 #include "parser.h"
 
 typedef enum {
-    AAC_AC3_PARSE_ERROR_SYNC        = -1,
-    AAC_AC3_PARSE_ERROR_BSID        = -2,
-    AAC_AC3_PARSE_ERROR_SAMPLE_RATE = -3,
-    AAC_AC3_PARSE_ERROR_FRAME_SIZE  = -4,
-    AAC_AC3_PARSE_ERROR_FRAME_TYPE  = -5,
-    AAC_AC3_PARSE_ERROR_CRC         = -6,
-    AAC_AC3_PARSE_ERROR_CHANNEL_CFG = -7,
+    AAC_AC3_PARSE_ERROR_SYNC        = -0x1030c0a,
+    AAC_AC3_PARSE_ERROR_BSID        = -0x2030c0a,
+    AAC_AC3_PARSE_ERROR_SAMPLE_RATE = -0x3030c0a,
+    AAC_AC3_PARSE_ERROR_FRAME_SIZE  = -0x4030c0a,
+    AAC_AC3_PARSE_ERROR_FRAME_TYPE  = -0x5030c0a,
+    AAC_AC3_PARSE_ERROR_CRC         = -0x6030c0a,
+    AAC_AC3_PARSE_ERROR_CHANNEL_CFG = -0x7030c0a,
 } AACAC3ParseError;
 
 typedef struct AACAC3ParseContext {