Minor simplifications to help with Null Safety

This simplifies the code a bit and helps the migration tool
to figure out the nullability correctly.

PiperOrigin-RevId: 321723762

lib/src/common/request_client.dart

diff --git a/lib/src/common/request_client.dart b/lib/src/common/request_client.dart
index 46be7ab..bd28618 100644
--- a/lib/src/common/request_client.dart
+++ b/lib/src/common/request_client.dart
@@ -43,8 +43,7 @@
     var exception;
     T response;
     try {
-      response = process(sendRaw(request));
-      return response;
+      return response = process(sendRaw(request));
     } catch (e) {
       exception = e;
       rethrow;
@@ -93,8 +92,7 @@
     var exception;
     T response;
     try {
-      response = process(await sendRaw(request));
-      return response;
+      return response = process(await sendRaw(request));
     } catch (e) {
       exception = e;
       rethrow;

lib/support/stdio_stepper.dart

diff --git a/lib/support/stdio_stepper.dart b/lib/support/stdio_stepper.dart
index e688c2b..9e4d47b 100644
--- a/lib/support/stdio_stepper.dart
+++ b/lib/support/stdio_stepper.dart
@@ -23,10 +23,7 @@
 LineReader _stdinLineReader;
 
 /// A [LineReader] instance connected to 'dart:io' [stdin].
-LineReader get stdinLineReader {
-  _stdinLineReader ??= LineReader(stdin);
-  return _stdinLineReader;
-}
+LineReader get stdinLineReader => _stdinLineReader ??= LineReader(stdin);
 
 /// Provides a command line interface for stepping through or skipping
 /// WebDriver commands.