[msh] try to complete module path

Msh can execute module directly. So try to auto-complete the path when
user press TAB. There is a chance that the path is a module.

components/finsh/msh.c

@@ -453,6 +453,15 @@ void msh_auto_complete(char *prefix)
 
             ptr --;
         }
+#ifdef RT_USING_MODULE
+        /* There is a chance that the user want to run the module directly. So
+         * try to complete the file names. If the completed path is not a
+         * module, the system won't crash anyway. */
+        if (ptr == prefix)
+        {
+            msh_auto_complete_path(ptr);
+        }
+#endif
     }
 #endif