Decrease the indentation in imported_source_file

Author: jyn514

compiler/rustc_metadata/src/rmeta/decoder.rs

@@ -1467,19 +1467,16 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
                 // `try_to_translate_virtual_to_real` don't have to worry about how the
                 // compiler is bootstrapped.
                 if let Some(virtual_dir) = &sess.opts.unstable_opts.simulate_remapped_rust_src_base
-                {
-                    if let Some(real_dir) = &sess.opts.real_rust_source_base_dir {
-                        for subdir in ["library", "compiler"] {
-                            if let rustc_span::FileName::Real(ref mut old_name) = name {
-                                if let rustc_span::RealFileName::LocalPath(local) = old_name {
-                                    if let Ok(rest) = local.strip_prefix(real_dir.join(subdir)) {
-                                        *old_name = rustc_span::RealFileName::Remapped {
-                                            local_path: None,
-                                            virtual_name: virtual_dir.join(subdir).join(rest),
-                                        };
-                                    }
-                                }
-                            }
+                && let Some(real_dir) = &sess.opts.real_rust_source_base_dir
+                && let rustc_span::FileName::Real(ref mut old_name) = name
+                && let rustc_span::RealFileName::LocalPath(local) = old_name {
+                    for subdir in ["library", "compiler"] {
+                        if let Ok(rest) = local.strip_prefix(real_dir.join(subdir)) {
+                            *old_name = rustc_span::RealFileName::Remapped {
+                                local_path: None,
+                                virtual_name: virtual_dir.join(subdir).join(rest),
+                            };
+                            break;
                         }
                     }
                 }