remove feature(nll) from #45157 test.

src/test/ui/issues/issue-40510-1.nll.stderr

@@ -1,13 +0,0 @@
-error: captured variable cannot escape `FnMut` closure body
-  --> $DIR/issue-40510-1.rs:7:9
-   |
-LL |     || {
-   |      - inferred to be a `FnMut` closure
-LL |         &mut x
-   |         ^^^^^^ returns a reference to a captured variable which escapes the closure body
-   |
-   = note: `FnMut` closures only have access to their captured variables while they are executing...
-   = note: ...therefore, they cannot allow references to captured variables to escape
-
-error: aborting due to previous error
-

src/test/ui/issues/issue-40510-3.nll.stderr

@@ -1,15 +0,0 @@
-error: captured variable cannot escape `FnMut` closure body
-  --> $DIR/issue-40510-3.rs:7:9
-   |
-LL |       || {
-   |        - inferred to be a `FnMut` closure
-LL | /         || {
-LL | |             x.push(())
-LL | |         }
-   | |_________^ returns a closure that contains a reference to a captured variable, which then escapes the closure body
-   |
-   = note: `FnMut` closures only have access to their captured variables while they are executing...
-   = note: ...therefore, they cannot allow references to captured variables to escape
-
-error: aborting due to previous error
-

src/test/ui/issues/issue-45157.rs

@@ -1,5 +1,4 @@
 #![allow(unused)]
-#![feature(nll)]
 
 // ignore-tidy-linelength
 

src/test/ui/issues/issue-45157.stderr

@@ -1,5 +1,5 @@
 error[E0502]: cannot borrow `u` (via `u.z.c`) as immutable because it is also borrowed as mutable (via `u.s.a`)
-  --> $DIR/issue-45157.rs:29:20
+  --> $DIR/issue-45157.rs:28:20
    |
 LL |         let mref = &mut u.s.a;
    |                    ---------- mutable borrow occurs here (via `u.s.a`)