livetree.c: Fix memory leak

When running coverity on dtc source code the following error is reported.

==========================================================================
*** CID 1370967:  Resource leaks  (RESOURCE_LEAK)
/tools/dtc/livetree.c: 850 in add_fixup_entry()
844		if (strchr(node->fullpath, ':') || strchr(prop->name, ':'))
845			die("arguments should not contain ':'\n");
846
847		xasprintf(&entry, "%s:%s:%u",
848			  node->fullpath, prop->name, m->offset);
849		append_to_property(fn, m->ref, entry, strlen(entry) + 1);
>>>     CID 1370967:  Resource leaks  (RESOURCE_LEAK)
>>>     Variable "entry" going out of scope leaks the storage it points to.
850     }
==========================================================================

Fix the leak.

Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

livetree.c

@@ -847,6 +847,8 @@ static void add_fixup_entry(struct dt_info *dti, struct node *fn,
 	xasprintf(&entry, "%s:%s:%u",
 			node->fullpath, prop->name, m->offset);
 	append_to_property(fn, m->ref, entry, strlen(entry) + 1);
+
+	free(entry);
 }
 
 static void generate_fixups_tree_internal(struct dt_info *dti,