flac: fix endless bytes skip

A hang was caused when the stream head is invalid and a header should be skipped, but not enough data is available. In this case, block_SkipBytes returns VLC_EGENERIC and does not seek anything. So, the same invalid block is processed again and again.

modules/packetizer/flac.c

@@ -459,7 +459,9 @@ static block_t *Packetize(decoder_t *p_dec, block_t **pp_block)
             msg_Warn(p_dec, "discarding bytes as we're over framesize %u, %zu",
                      p_sys->stream_info.max_framesize,
                      p_sys->i_offset);
-            block_SkipBytes( &p_sys->bytestream, FLAC_HEADER_SIZE_MAX + 2 );
+            if( block_SkipBytes( &p_sys->bytestream,
+                                 FLAC_HEADER_SIZE_MAX + 2 ) != VLC_SUCCESS )
+                return NULL;
             block_BytestreamFlush( &p_sys->bytestream );
             p_sys->crc = 0;
             p_sys->i_buf_offset = 0;