[cleanup] Convert XMALLOC/memset to XCALLOC

Simple conversion of XMALLOC/memset to XCALLOC
diff --git a/lib/hash.c b/lib/hash.c
index 3884051..672327e 100644
--- a/lib/hash.c
+++ b/lib/hash.c
@@ -32,9 +32,8 @@
   struct hash *hash;
 
   hash = XMALLOC (MTYPE_HASH, sizeof (struct hash));
-  hash->index = XMALLOC (MTYPE_HASH_INDEX, 
+  hash->index = XCALLOC (MTYPE_HASH_INDEX,
 			 sizeof (struct hash_backet *) * size);
-  memset (hash->index, 0, sizeof (struct hash_backet *) * size);
   hash->size = size;
   hash->hash_key = hash_key;
   hash->hash_cmp = hash_cmp;