Update src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-one.rs

Co-Authored-By: matthewjasper <mjjasper1@gmail.com>

Author: nikomatsakis

src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-one.rs

@@ -14,7 +14,7 @@ async fn async_ret_impl_trait1<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a> {
     (a, b)
 }
 
-// As above, but `'b: 'a`, so return type ca be inferred to `(&'a u8,
+// As above, but `'b: 'a`, so return type can be inferred to `(&'a u8,
 // &'a u8)`.
 async fn async_ret_impl_trait2<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a>
 where