doc(test_suite): fix the incorrect description of the test case interrupt_priority

Author: yvt

src/constance_test_suite/src/kernel_tests/interrupt_priority.rs

@@ -1,6 +1,5 @@
-//! Validates error codes returned by interrupt line manipulation methods. Also,
-//! checks miscellaneous properties of interrupt lines.
-//! TODO: This description is wrong
+//! Makes sure that interrupt priorities affect the order in which interrupt
+//! handlers are called.
 use constance::{
     kernel::{Hunk, InterruptHandler, InterruptLine, Task},
     prelude::*,