Added rtems exit code to ping, route, and ifconfig commands.

The rtems shell commands should not exit but allow multiple
command attempts and some of the commands share code that
will exit.  For this reason a common exit routine was
provided and code added to err.h to address this.

allow access to it.

freebsd-userspace/include/err.h

@@ -52,6 +52,19 @@
 #include <sys/_types.h>
 #endif
 
+#ifdef __rtems__
+#include <setjmp.h>
+typedef struct  rtems_shell_globals_s {
+  jmp_buf exit_jmp;
+  int     exit_code;
+} rtems_shell_globals_t;
+extern rtems_shell_globals_t *rtems_shell_globals;
+void rtems_shell_exit (int code);
+
+#define exit rtems_shell_exit
+#endif
+
+
 __BEGIN_DECLS
 void	err(int, const char *, ...) __dead2 __printf0like(2, 3);
 void	verr(int, const char *, __va_list) __dead2 __printf0like(2, 0);