Fix typos (taking into account review comments)

Author: blyxyas

clippy_lints/src/methods/needless_collect.rs

@@ -127,7 +127,7 @@ pub(super) fn check<'tcx>(
     }
 }
 
-/// checks for for collecting into a (generic) method or function argument
+/// checks for collecting into a (generic) method or function argument
 /// taking an `IntoIterator`
 fn check_collect_into_intoiterator<'tcx>(
     cx: &LateContext<'tcx>,

tests/ui/ptr_arg.rs

@@ -282,7 +282,7 @@ mod issue_9218 {
         todo!()
     }
 
-    // These two's return types don't use use 'a so it's not okay
+    // These two's return types don't use 'a so it's not okay
     fn cow_bad_ret_ty_1<'a>(input: &'a Cow<'a, str>) -> &'static str {
         //~^ ERROR: using a reference to `Cow` is not recommended
         todo!()