Fix compilation warnings in generated code

Patch taken from open bug report http://savannah.gnu.org/bugs/?40243
(project gengetopt seems to be dead; no hope for a new release soon)

Imported by Philippe Mariman.
This description by Thomas De Schampheleire.

Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>

Index: gengetopt-2.22.6/src/skels/c_source.cc
===================================================================
--- gengetopt-2.22.6.orig/src/skels/c_source.cc	2012-11-07 20:58:29.000000000 +0100
+++ gengetopt-2.22.6/src/skels/c_source.cc	2014-11-20 12:05:02.597527761 +0100
@@ -2424,9 +2424,12 @@
       stream << "  FIX_UNUSED (field);";
       stream << "\n";
       stream << indent_str;
+      stream << "  FIX_UNUSED (stop_char);";
+      stream << "\n";
+      stream << indent_str;
+      stream << "  FIX_UNUSED (val);";
       stream << "\n";
       stream << indent_str;
-      stream << "  stop_char = 0;";
       stream << "\n";
       stream << indent_str;
       stream << "  found = 0;";
@@ -3981,6 +3984,12 @@
       stream << "\n";
       stream << indent_str;
     }
+  else
+    {
+      stream << "  FIX_UNUSED (check_required);";
+      stream << "\n";
+      stream << indent_str;
+    }
   stream << "\n";
   stream << indent_str;
   indent = 2;
Index: gengetopt-2.22.6/src/skels/c_source.h_skel
===================================================================
--- gengetopt-2.22.6.orig/src/skels/c_source.h_skel	2012-11-02 18:43:24.000000000 +0100
+++ gengetopt-2.22.6/src/skels/c_source.h_skel	2014-11-20 12:05:22.501528424 +0100
@@ -767,8 +767,9 @@
   char **string_field;
 @ENDIF@
   FIX_UNUSED (field);
+  FIX_UNUSED (stop_char);
+  FIX_UNUSED (val);
 
-  stop_char = 0;
   found = 0;
 
   if (!multiple_option && prev_given && (*prev_given || (check_ambiguity && *field_given)))
@@ -1327,6 +1328,8 @@
     {
       error_occurred += @parser_name@_required2 (args_info, argv[0], additional_error);
     }
+@ELSE@
+  FIX_UNUSED (check_required);
 @ENDIF@
 
   @parser_name@_release (&local_args_info);