cdf: fix memleak in dav1d_cdf_thread_unref

Observed with
clusterfuzz-testcase-minimized-dav1d_fuzzer_mt-5700224002031616. Credits
to oss-fuzz.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/cdf.c b/src/cdf.c
index 4987354..c608619 100644
--- a/src/cdf.c
+++ b/src/cdf.c
@@ -4200,9 +4200,9 @@ void dav1d_cdf_thread_ref(CdfThreadContext *const dst,
 }
 
 void dav1d_cdf_thread_unref(CdfThreadContext *const cdf) {
-    memset(cdf, 0, sizeof(*cdf));
     if (cdf->ref)
         dav1d_ref_dec(&cdf->ref);
+    memset(cdf, 0, sizeof(*cdf));
 }
 
 void dav1d_cdf_thread_wait(CdfThreadContext *const cdf) {