CODING_STYLE: add exception for for (int i=0, ...) declarations

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

CODING_STYLE

@@ -46,6 +46,7 @@
 - declare variables at the top, try to keep them as local as possible.
   Exception: if the same variable is re-used in multiple blocks, declare it
   at the top.
+  Exception: basic loop variables, e.g. for (int i = 0; ...)
 
   int a;
   int c;