[Minor] Fix another include path

contrib/zstd/zstd_decompress_block.h

@@ -16,7 +16,7 @@
  *  Dependencies
  *********************************************************/
 #include "zstd_deps.h"   /* size_t */
-#include "../zstd.h"    /* DCtx, and some public functions */
+#include "zstd.h"    /* DCtx, and some public functions */
 #include "zstd_internal.h"  /* blockProperties_t, and some public functions */
 #include "zstd_decompress_internal.h"  /* ZSTD_seqSymbol */