[jfern:nova/dev-bitstruct 10/10] warning: equal expressions as operands to `-`

[kernel test robot <lkp@intel.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git nova/dev-bitstruct
head:   b32d7e59ee65f3aa21afc5c467495cac8fd5703f
commit: b32d7e59ee65f3aa21afc5c467495cac8fd5703f [10/10] Add hardening for out of bounds access
config: x86_64-rhel-9.4-rust (https://download.01.org/0day-ci/archive/20250924/202509242340.kTk9JeC6-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
rustc: rustc 1.88.0 (6b00bc388 2025-06-23)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250924/202509242340.kTk9JeC6-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202509242340.kTk9JeC6-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> warning: equal expressions as operands to `-`
   --> rust/kernel/bits/bitfield.rs:311:32
   |
   311 |             const BITS: u32 = ($hi - $lo + 1) as u32;
   |                                ^^^^^^^^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#eq_op
   = note: `-W clippy::eq-op` implied by `-W clippy::all`
   = help: to override `-W clippy::all` add `#[allow(clippy::eq_op)]`
--
>> warning: this operation has no effect
   --> rust/kernel/bits/bitfield.rs:311:32
   |
   311 |             const BITS: u32 = ($hi - $lo + 1) as u32;
   |                                ^^^^^^^^^ help: consider reducing it to: `$hi`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#identity_op
   = note: `-W clippy::identity-op` implied by `-W clippy::all`
   = help: to override `-W clippy::all` add `#[allow(clippy::identity_op)]`

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki