Add local prototype for rtems_shell_main_monitor.

testsuites/libtests/monitor02/init.c

@@ -21,6 +21,12 @@
 #include <rtems/shellconfig.h>
 #define MAX_ARGS 128
 
+/*
+ * HACK: API visibility violation
+ * rtems_shell_main_monitor should better be declared in rtems/shell.h 
+ */
+extern int rtems_shell_main_monitor(int argc, char **argv);
+
 char        *Commands[] = {
   "task",
   "task 32",