Changed function argument names.

Changed function argument names to suppress compile warnings:
panel.h:143: warning: declaration of 'index' shadows a global declaration
panel.h:144: warning: declaration of 'index' shadows a global declaration

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

src/panel.h

@@ -140,8 +140,8 @@ void select_item (WPanel *panel);
 extern Hook *select_file_hook;
 
 void recalculate_panel_summary (WPanel *panel);
-void file_mark (WPanel *panel, int index, int val);
-void do_file_mark (WPanel *panel, int index, int val);
+void file_mark (WPanel *panel, int idx, int val);
+void do_file_mark (WPanel *panel, int idx, int val);
 
 void directory_history_next (WPanel *panel);
 void directory_history_prev (WPanel *panel);
@@ -158,4 +158,4 @@ const char **panel_get_user_possible_fields(gsize *);
 void panel_init(void);
 void panel_deinit(void);
 
-#endif
+#endif					/* MC_PANEL_H */