fix test

Author: Cyan4973

tests/cli-tests/file-stat/compress-file-to-dir-without-write-perm.sh.stderr.exact

@@ -23,4 +23,6 @@ Trace:FileStat:  > UTIL_stat(-1, out/file.zst)
 Trace:FileStat:  < 0
 Trace:FileStat: < 0
 zstd: out/file.zst: Permission denied
+Trace:FileStat: > UTIL_isFileDescriptorPipe(out/file.zst)
+Trace:FileStat: < 0
 zstd: can't stat out/file.zst : Permission denied -- ignored