#213319 by add1sun: minor code documentation fix at template_preprocess_block()

includes/theme.inc

@@ -1890,7 +1890,7 @@ function template_preprocess_node(&$variables) {
  * series of template file suggestions. If none are found, the default
  * block.tpl.php is used.
  *
- * Most themes utilize their own copy of page.tpl.php. The default is located
+ * Most themes utilize their own copy of block.tpl.php. The default is located
  * inside "modules/system/block.tpl.php". Look in there for the full list of
  * variables.
  *