message: revise some comments
diff: @@ -410,7 +410,7 @@ fn detect_from_mp() -> Result<PhysAddr, ()> {
  addr += mem::size_of::<ApicConfigTable>();
  for _i in 0..mp_config.entry_count {
  match unsafe { *(addr as *const u8) } {
  - // cpu entry
  + // CPU entry
  0 => {
  let cpu_entry: &ApicProcessorEntry =
  unsafe { &*(addr as *const ApicProcessorEntry) };
  @@ -419,7 +419,7 @@ fn detect_from_mp() -> Result<PhysAddr, ()> {
  }
  addr += mem::size_of::<ApicProcessorEntry>();
  }
  - // IO_APIC
  + // IO-APIC entry
  2 => {
  let io_entry: &ApicIoEntry = unsafe { &*(addr as *const ApicIoEntry) };
  let ioapic = io_entry.addr;
  