getrlimit: delegate inquiries about fs resource

This commit corrects following system/library calls.
* getdtablesize()
* getrlimit(RLIMIT_FSIZE/RLIMIT_LOCKS/RLIMIT_NOFILE)
* sysconf(_SC_OPEN_MAX)
* ulimit(UL_GETFSIZE)

refs #31
refs #32

kernel/syscall.c

@@ -1843,6 +1843,13 @@ SYSCALL_DECLARE(getrlimit)
 		ret = 0;
 		break;
 
+	case RLIMIT_FSIZE:
+	case RLIMIT_LOCKS:
+	case RLIMIT_NOFILE:
+		/* just forward */
+		ret = syscall_generic_forwarding(n, ctx);
+		break;
+
 	default:
 
 		return -ENOSYS;