[libxml2] Fix an error in previous commit

[Daniel Veillard <veillard src gnome org>]

commit baaf03f80f817bb34c421421e6cb4d68c353ac9a
Author: Aron Xu <happyaron xu gmail com>
Date:   Fri Jul 20 15:41:34 2012 +0800

    Fix an error in previous commit

 entities.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/entities.c b/entities.c
index 859ec3b..7d06820 100644
--- a/entities.c
+++ b/entities.c
@@ -529,7 +529,7 @@ xmlGetDocEntity(xmlDocPtr doc, const xmlChar *name) {
  */
 #define growBufferReentrant() {						\
     xmlChar *tmp;                                                       \
-    size_t new_size = buffer_size *= 2;                                 \
+    size_t new_size = buffer_size * 2;                                  \
     if (new_size < buffer_size) goto mem_error;                         \
     tmp = (xmlChar *) xmlRealloc(buffer, new_size);	                \
     if (tmp == NULL) goto mem_error;                                    \