Fix segfault.

Index: lzf/lzf_filter.c
--- lzf/lzf_filter.c.orig
+++ lzf/lzf_filter.c
@@ -249,7 +249,7 @@ size_t lzf_filter(unsigned flags, size_t cd_nelmts,
 
     if(status != 0){
 
-        free(*buf);
+        H5free_memory(*buf);
         *buf = outbuf;
         *buf_size = outbuf_size;
 
