let_chains: Adjust unnecessary parens tests.

src/test/ui/lint/lint-unnecessary-parens.rs

@@ -22,8 +22,8 @@ fn main() {
     match (true) { //~ ERROR unnecessary parentheses around `match` head expression
         _ => {}
     }
-    if let 1 = (1) {} //~ ERROR unnecessary parentheses around `if let` head expression
-    while let 1 = (2) {} //~ ERROR unnecessary parentheses around `while let` head expression
+    if let 1 = (1) {} //~ ERROR unnecessary parentheses around `let` scrutinee
+    while let 1 = (2) {} //~ ERROR unnecessary parentheses around `let` scrutinee
     let v = X { y: false };
     // struct lits needs parens, so these shouldn't warn.
     if (v == X { y: true }) {}

src/test/ui/lint/lint-unnecessary-parens.stderr

@@ -40,13 +40,13 @@ error: unnecessary parentheses around `match` head expression
 LL |     match (true) {
    |           ^^^^^^ help: remove these parentheses
 
-error: unnecessary parentheses around `if let` head expression
+error: unnecessary parentheses around `let` scrutinee
   --> $DIR/lint-unnecessary-parens.rs:25:16
    |
 LL |     if let 1 = (1) {}
    |                ^^^ help: remove these parentheses
 
-error: unnecessary parentheses around `while let` head expression
+error: unnecessary parentheses around `let` scrutinee
   --> $DIR/lint-unnecessary-parens.rs:26:19
    |
 LL |     while let 1 = (2) {}