*: Remove some for statement declarations

We generally require C99.  Some compilers, e.g.  gcc, barf on
'for' statement declared variables, if std={gnu,c}99 or higher is not
given - even while seemingly accepting other C99 constructs.

As it's trivial, remove these.
diff --git a/lib/zclient.c b/lib/zclient.c
index c2e1333..09bb180 100644
--- a/lib/zclient.c
+++ b/lib/zclient.c
@@ -886,6 +886,7 @@
 {
   size_t w;
   struct if_link_params *iflp;
+  int i;
   
   if (s == NULL || ifp == NULL || ifp->link_params == NULL)
     return 0;
@@ -900,7 +901,7 @@
   w += stream_putf (s, iflp->max_rsv_bw);
   
   w += stream_putl (s, MAX_CLASS_TYPE);
-  for (int i = 0; i < MAX_CLASS_TYPE; i++)
+  for (i = 0; i < MAX_CLASS_TYPE; i++)
     w += stream_putf (s, iflp->unrsv_bw[i]);
   
   w += stream_putl (s, iflp->admin_grp);