For display unsigned better than signed char

git-svn-id: http://svn.eurecom.fr/openair4G/trunk@5678 818b1a75-f10b-46b9-bf7c-635c3b92a50f

openair2/UTIL/MEM/mem_block.h

@@ -52,7 +52,7 @@ typedef struct mem_block_t{
   struct mem_block_t *next;
   struct mem_block_t *previous;
   unsigned char pool_id;
-  char *data;
+  unsigned char *data;
 }mem_block_t;
 #include "UTIL/LISTS/list.h"