#386 C99 restriction

[Stefan Haubenthal]

This patch fixes the restriction

--- joe/bw.c.bak    2018-01-10 18:28:34 +0100
+++ joe/bw.c    2018-03-15 01:11:13 +0100
@@ -1227,8 +1227,8 @@
 {
    BW *bw;
    off_t amnt;
-   WIND_BW(bw, w);
    int rtn = -1;
+   WIND_BW(bw, w);

    if (opt_left < 0)
        amnt = bw->w / (-opt_left);

[John J. Jordan]

C99 formally removed this restriction. GCC hasn't enforced it in a very long time. Until a couple versions ago, MSVC required this but even they have finally updated the C frontend. Twenty-plus years on, I don't think this is much of a concern, unless we see specific build breaks as a result. Closing.