lcl: return negative error codes on decode_init() errors.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

libavcodec/lcldec.c

@@ -481,7 +481,7 @@ static av_cold int decode_init(AVCodecContext *avctx)
 
     if (avctx->extradata_size < 8) {
         av_log(avctx, AV_LOG_ERROR, "Extradata size too small.\n");
-        return 1;
+        return AVERROR_INVALIDDATA;
     }
 
     /* Check codec type */
@@ -530,7 +530,7 @@ static av_cold int decode_init(AVCodecContext *avctx)
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "Unsupported image format %d.\n", c->imgtype);
-        return 1;
+        return AVERROR_INVALIDDATA;
     }
 
     /* Detect compression method */
@@ -547,7 +547,7 @@ static av_cold int decode_init(AVCodecContext *avctx)
             break;
         default:
             av_log(avctx, AV_LOG_ERROR, "Unsupported compression format for MSZH (%d).\n", c->compression);
-            return 1;
+            return AVERROR_INVALIDDATA;
         }
         break;
 #if CONFIG_ZLIB_DECODER
@@ -565,7 +565,7 @@ static av_cold int decode_init(AVCodecContext *avctx)
         default:
             if (c->compression < Z_NO_COMPRESSION || c->compression > Z_BEST_COMPRESSION) {
                 av_log(avctx, AV_LOG_ERROR, "Unsupported compression level for ZLIB: (%d).\n", c->compression);
-                return 1;
+                return AVERROR_INVALIDDATA;
             }
             av_log(avctx, AV_LOG_DEBUG, "Compression level for ZLIB: (%d).\n", c->compression);
         }
@@ -573,14 +573,14 @@ static av_cold int decode_init(AVCodecContext *avctx)
 #endif
     default:
         av_log(avctx, AV_LOG_ERROR, "BUG! Unknown codec in compression switch.\n");
-        return 1;
+        return AVERROR_INVALIDDATA;
     }
 
     /* Allocate decompression buffer */
     if (c->decomp_size) {
         if ((c->decomp_buf = av_malloc(max_decomp_size)) == NULL) {
             av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
-            return 1;
+            return AVERROR(ENOMEM);
         }
     }
 
@@ -606,7 +606,7 @@ static av_cold int decode_init(AVCodecContext *avctx)
         if (zret != Z_OK) {
             av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
             av_freep(&c->decomp_buf);
-            return 1;
+            return AVERROR_UNKNOWN;
         }
     }
 #endif