zerocodec: Cosmetics

Be consistent with error messages and code formatting.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

libavcodec/zerocodec.c

@@ -33,7 +33,8 @@ static int zerocodec_decode_frame(AVCodecContext *avctx, void *data,
     AVFrame *pic         = avctx->coded_frame;
     AVFrame *prev_pic    = &zc->previous_frame;
     z_stream *zstream    = &zc->zstream;
-    uint8_t *prev = prev_pic->data[0], *dst;
+    uint8_t *prev        = prev_pic->data[0];
+    uint8_t *dst;
     int i, j, zret;
 
     pic->reference = 3;
@@ -43,7 +44,7 @@ static int zerocodec_decode_frame(AVCodecContext *avctx, void *data,
         pic->pict_type = AV_PICTURE_TYPE_I;
     } else {
         if (!prev) {
-            av_log(avctx, AV_LOG_ERROR, "Missing reference frame!\n");
+            av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
             return AVERROR_INVALIDDATA;
         }
         pic->key_frame = 0;
@@ -56,10 +57,9 @@ static int zerocodec_decode_frame(AVCodecContext *avctx, void *data,
     }
 
     zret = inflateReset(zstream);
-
     if (zret != Z_OK) {
-        av_log(avctx, AV_LOG_ERROR, "Could not reset inflate: %d\n", zret);
-        return AVERROR(EINVAL);
+        av_log(avctx, AV_LOG_ERROR, "Could not reset inflate: %d.\n", zret);
+        return AVERROR_INVALIDDATA;
     }
 
     zstream->next_in  = avpkt->data;
@@ -79,8 +79,8 @@ static int zerocodec_decode_frame(AVCodecContext *avctx, void *data,
         zret = inflate(zstream, Z_SYNC_FLUSH);
         if (zret != Z_OK && zret != Z_STREAM_END) {
             av_log(avctx, AV_LOG_ERROR,
-                   "Inflate failed with return code: %d\n", zret);
-            return AVERROR(EINVAL);
+                   "Inflate failed with return code: %d.\n", zret);
+            return AVERROR_INVALIDDATA;
         }
 
         if (!(avpkt->flags & AV_PKT_FLAG_KEY))
@@ -138,14 +138,12 @@ static av_cold int zerocodec_decode_init(AVCodecContext *avctx)
     zstream->opaque = Z_NULL;
 
     zret = inflateInit(zstream);
-
     if (zret != Z_OK) {
-        av_log(avctx, AV_LOG_ERROR, "Could not initialize inflate: %d\n", zret);
+        av_log(avctx, AV_LOG_ERROR, "Could not initialize inflate: %d.\n", zret);
         return AVERROR(ENOMEM);
     }
 
     avctx->coded_frame = avcodec_alloc_frame();
-
     if (!avctx->coded_frame) {
         av_log(avctx, AV_LOG_ERROR, "Could not allocate frame buffer.\n");
         zerocodec_decode_close(avctx);