Also free default_password and ch_comment when freeing a zip structure.

Missing free for ch_comment noted by Pierre Joye.

--HG--
branch : HEAD

lib/zip_free.c

diff --git a/lib/zip_free.c b/lib/zip_free.c
index 76c3a96..9932c14 100644
--- a/lib/zip_free.c
+++ b/lib/zip_free.c
@@ -57,7 +57,9 @@
     if (za->zp)
 	fclose(za->zp);
 
+    free(za->default_password);
     _zip_cdir_free(za->cdir);
+    free(za->ch_comment);
 
     if (za->entry) {
 	for (i=0; i<za->nentry; i++) {