Update XZ Utils to 5.0.3 (in deps)

src/liblzma/api/lzma/block.h

Index: src/liblzma/api/lzma/block.h
===================================================================
--- src/liblzma/api/lzma/block.h	(revision 50504)
+++ src/liblzma/api/lzma/block.h	(working copy)
@@ -318,8 +318,8 @@
  * The size of the Block Header must have already been decoded with
  * lzma_block_header_size_decode() macro and stored to block->header_size.
  *
- * block->filters must have been allocated, but not necessarily initialized.
- * Possible existing filter options are _not_ freed.
+ * block->filters must have been allocated, but they don't need to be
+ * initialized (possible existing filter options are not freed).
  *
  * \param       block       Destination for Block options.
  * \param       allocator   lzma_allocator for custom allocator functions.
@@ -483,6 +483,7 @@
  *
  * \return      - LZMA_OK: Encoding was successful.
  *              - LZMA_BUF_ERROR: Not enough output buffer space.
+ *              - LZMA_UNSUPPORTED_CHECK
  *              - LZMA_OPTIONS_ERROR
  *              - LZMA_MEM_ERROR
  *              - LZMA_DATA_ERROR