Stop using deprecated reset?Stream functions

These are replaced by the corresponding context resets. When
converting resetCStream, CCtx_setPledgedSrcSize isn't called if the
source size is "unknown".

This helps reduce the reliance on "static only" symbols, as well as
reducing the use of deprecated functions.

Signed-off-by: Stephen Kitt <steve@sk2.org>

contrib/seekable_format/zstdseek_decompress.c

@@ -394,7 +394,7 @@ size_t ZSTD_seekable_decompress(ZSTD_seekable* zs, void* dst, size_t len, unsign
                                   SEEK_SET));
             zs->in = (ZSTD_inBuffer){zs->inBuff, 0, 0};
             XXH64_reset(&zs->xxhState, 0);
-            ZSTD_resetDStream(zs->dstream);
+            ZSTD_DCtx_reset(zs->dstream, ZSTD_reset_session_only);
         }
 
         while (zs->decompressedOffset < offset + len) {