libbacktrace patch committed: Avoid ZSTD_CLEVEL_DEFAULT

[Ian Lance Taylor]

PR 117812 reports a libbacktrace test failure when building with a
2018 version of zstd, because ZSTD_CLEVEL_DEFAULT is not defined.
This patch avoids using it, replacing it with the default value 3.
The test doesn't really care what compression level is used anyhow.
Bootstrapped and ran libbacktrace tests on x86_64-pc-linux-gnu.
Committed to mainline.

Ian

            PR libbacktrace/117812
            * zstdtest.c (test_large): Use 3 rather than ZSTD_CLEVEL_DEFAULT

3e343ef7f0ac0eb9e526b4f6d3bf3f69be3f0684
diff --git a/libbacktrace/zstdtest.c b/libbacktrace/zstdtest.c
index b9552ab1b88..eb572a24e52 100644
--- a/libbacktrace/zstdtest.c
+++ b/libbacktrace/zstdtest.c
@@ -379,8 +379,7 @@ test_large (struct backtrace_state *state ATTRIBUTE_UNUSED)
     }
 
   r = ZSTD_compress (compressed_buf, compressed_bufsize,
-                    orig_buf, orig_bufsize,
-                    ZSTD_CLEVEL_DEFAULT);
+                    orig_buf, orig_bufsize, 3);
   if (ZSTD_isError (r))
     {
       fprintf (stderr, "zstd compress failed: %s\n", ZSTD_getErrorName (r));