avformat/apngdec: Remove goto fail that does nothing

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavformat/apngdec.c

@@ -151,17 +151,17 @@ static int apng_read_header(AVFormatContext *s)
     uint32_t len, tag;
     AVStream *st;
     int acTL_found = 0;
-    int64_t ret = AVERROR_INVALIDDATA;
+    int64_t ret;
 
     /* verify PNGSIG */
     if (avio_rb64(pb) != PNGSIG)
-        return ret;
+        return AVERROR_INVALIDDATA;
 
     /* parse IHDR (must be first chunk) */
     len = avio_rb32(pb);
     tag = avio_rl32(pb);
     if (len != 13 || tag != MKTAG('I', 'H', 'D', 'R'))
-        return ret;
+        return AVERROR_INVALIDDATA;
 
     st = avformat_new_stream(s, NULL);
     if (!st)
@@ -193,11 +193,9 @@ static int apng_read_header(AVFormatContext *s)
             int64_t size   = avio_size(pb);
             int64_t offset = avio_tell(pb);
             if (size < 0) {
-                ret = size;
-                goto fail;
+                return size;
             } else if (offset < 0) {
-                ret = offset;
-                goto fail;
+                return offset;
             } else if ((ret = ffio_ensure_seekback(pb, size - offset)) < 0) {
                 av_log(s, AV_LOG_WARNING, "Could not ensure seekback, will not loop\n");
                 ctx->num_play = 1;
@@ -205,20 +203,18 @@ static int apng_read_header(AVFormatContext *s)
         }
         if ((ctx->num_play == 1 || !acTL_found) &&
             ((ret = ffio_ensure_seekback(pb, 4 /* len */ + 4 /* tag */)) < 0))
-            goto fail;
+            return ret;
 
         len = avio_rb32(pb);
-        if (len > INT_MAX - 12) {
-            ret = AVERROR_INVALIDDATA;
-            goto fail;
-        }
+        if (len > INT_MAX - 12)
+            return AVERROR_INVALIDDATA;
 
         tag = avio_rl32(pb);
         switch (tag) {
         case MKTAG('a', 'c', 'T', 'L'):
             if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0 ||
                 (ret = append_extradata(st->codecpar, pb, len + 12)) < 0)
-                goto fail;
+                return ret;
             acTL_found = 1;
             ctx->num_frames = AV_RB32(st->codecpar->extradata + ret + 8);
             ctx->num_play   = AV_RB32(st->codecpar->extradata + ret + 12);
@@ -227,21 +223,17 @@ static int apng_read_header(AVFormatContext *s)
             break;
         case MKTAG('f', 'c', 'T', 'L'):
             if (!acTL_found || len != 26) {
-               ret = AVERROR_INVALIDDATA;
-               goto fail;
+                return AVERROR_INVALIDDATA;
             }
             if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0)
-                goto fail;
+                return ret;
             return 0;
         default:
             if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0 ||
                 (ret = append_extradata(st->codecpar, pb, len + 12)) < 0)
-                goto fail;
+                return ret;
         }
     }
-
-fail:
-    return ret;
 }
 
 static int decode_fctl_chunk(AVFormatContext *s, APNGDemuxContext *ctx, AVPacket *pkt)