Typo on error E0369 description text

[FSciammarella]

Got this error message when trying to compile a crate using rustc 1.42.0-nightly (8597644 2020-01-07).

error[E0369]: cannot substract `systemstat::ByteSize` from `systemstat::ByteSize`
  --> /home/felipe-wsl/.cargo/registry/src/github.com-1ecc6299db9ec823/hegemon-0.1.0/src/providers/memory.rs:37:44         |
37 |                         Some((memory.total - memory.free).as_usize() as f64)
   |                               ------------ ^ ----------- systemstat::ByteSize
   |                               |
   |                               systemstat::ByteSize
   |
   = note: an implementation of `std::ops::Sub` might be missing for `systemstat::ByteSize`

The text reads substract instead of subtract.

[varkor]

@FSciammarella: if you want to contribute a fix, you would just need to modify these three lines:

rust/src/librustc_typeck/check/op.rs

Line 333 in ed6468d

format!("cannot substract `{}` from `{}`", rhs_ty, lhs_ty),

rust/src/test/ui/issues/issue-28837.rs

Line 8 in ed6468d

a - a; //~ ERROR cannot substract `A` from `A`

rust/src/test/ui/issues/issue-28837.stderr

Line 11 in ed6468d

error[E0369]: cannot substract `A` from `A`

[FSciammarella]

@varkor thanks for your response, I submitted a PR #68023 to fix this.