unused variable: g.restoring

Get rid of the last reference to 'g.restoring' (which managed to
unintentionally survive the change to 'g.program_state.restoring').

Also have suppress_map_output() check 'g.program_state.saving' and
switch the couple of checks against that flag to use the function.

src/restore.c

@@ -756,7 +756,9 @@ dorecover(NHFILE* nhfp)
     int rtmp;
     struct obj *otmp;
 
+    /* suppress map display if some part of the code tries to update that */
     g.program_state.restoring = 1;
+
     get_plname_from_file(nhfp, g.plname);
     getlev(nhfp, 0, (xchar) 0);
     if (!restgamestate(nhfp, &stuckid, &steedid)) {