Get rid of compiler warning about retval being used (returned) without
being initialized.  (gcc warning and Coverity 202)
diff --git a/Modules/_bsddb.c b/Modules/_bsddb.c
index bc70cc3..11e0201 100644
--- a/Modules/_bsddb.c
+++ b/Modules/_bsddb.c
@@ -4765,7 +4765,7 @@
 {
     int err;
     DBT key;
-    PyObject *retval;
+    PyObject *retval = NULL;
     key.flags = DB_DBT_MALLOC;
     CHECK_SEQUENCE_NOT_CLOSED(self)
     MYDB_BEGIN_ALLOW_THREADS