remove trailing space

crates/hir_ty/src/lower.rs

@@ -1676,7 +1676,7 @@ pub(crate) fn lower_to_chalk_mutability(m: hir_def::type_ref::Mutability) -> Mut
 
 /// Checks if the provided generic arg matches its expected kind, then lower them via
 /// provided closures. Use unknown if there was kind mismatch.
-/// 
+///
 /// Returns `Some` of the lowered generic arg. `None` if the provided arg is a lifetime.
 pub(crate) fn generic_arg_to_chalk<'a, T>(
     db: &dyn HirDatabase,