apr_encode_base32: fix advertised output *len when called with dst == NULL.


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1883868 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/encoding/apr_encode.c b/encoding/apr_encode.c
index e44ae11..b3278c7 100644
--- a/encoding/apr_encode.c
+++ b/encoding/apr_encode.c
@@ -665,7 +665,7 @@
     }
 
     if (len) {
-        *len = ((slen + 2) / 3 * 4) + 1;
+        *len = ((slen + 4) / 5 * 8) + 1;
     }
 
     return APR_SUCCESS;