avcodec/gdv: Replace assert() checking bitstream by if()

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

libavcodec/gdv.c

@@ -358,7 +358,8 @@ static int decompress_68(AVCodecContext *avctx, unsigned skip, unsigned use8)
                     if (val != ((1 << lbits) - 1)) {
                         break;
                     }
-                    assert(lbits < 16);
+                    if (lbits >= 16)
+                        return AVERROR_INVALIDDATA;
                 }
                 for (i = 0; i < len; i++) {
                     bytestream2_put_byte(pb, bytestream2_get_byte(gb));