Delete MacCall case from pretty-printing semicolon after StmtKind::Expr

I didn't figure out how to reach this condition with `expr` containing
`ExprKind::MacCall`. All the approaches I tried ended up with the macro
call ending up in the `StmtKind::MacCall` case below instead.

In any case, from visual inspection this is a bugfix. If we do end up
with a `StmtKind::Expr` containing `ExprKind::MacCall` with brace
delimiter, it would not need ";" printed after it.

Author: dtolnay

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -1101,10 +1101,7 @@ impl<'a> State<'a> {
                     false,
                     FixupContext { stmt: true, ..FixupContext::default() },
                 );
-                if match expr.kind {
-                    ast::ExprKind::MacCall(_) => true,
-                    _ => classify::expr_requires_semi_to_be_stmt(expr),
-                } {
+                if classify::expr_requires_semi_to_be_stmt(expr) {
                     self.word(";");
                 }
             }