Fix some -Wunreachable-code-aggressive warnings

Bug: chromium:1066980
Change-Id: I24fea094f28577799c5fcbcf2e9657ffa9bfd076
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/228760
Reviewed-by: Jamie Walch <jamiewalch@chromium.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Commit-Queue: Tommi <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34766}
diff --git a/modules/audio_processing/aec3/aec3_common.cc b/modules/audio_processing/aec3/aec3_common.cc
index 7bd8d62..3ba10d5 100644
--- a/modules/audio_processing/aec3/aec3_common.cc
+++ b/modules/audio_processing/aec3/aec3_common.cc
@@ -29,9 +29,9 @@
 
 #if defined(WEBRTC_HAS_NEON)
   return Aec3Optimization::kNeon;
-#endif
-
+#else
   return Aec3Optimization::kNone;
+#endif
 }
 
 float FastApproxLog2f(const float in) {
diff --git a/modules/desktop_capture/screen_capturer_linux.cc b/modules/desktop_capture/screen_capturer_linux.cc
index ed48b7d..6cad2ac 100644
--- a/modules/desktop_capture/screen_capturer_linux.cc
+++ b/modules/desktop_capture/screen_capturer_linux.cc
@@ -34,9 +34,9 @@
 
 #if defined(WEBRTC_USE_X11)
   return ScreenCapturerX11::CreateRawScreenCapturer(options);
-#endif  // defined(WEBRTC_USE_X11)
-
+#else
   return nullptr;
+#endif  // defined(WEBRTC_USE_X11)
 }
 
 }  // namespace webrtc
diff --git a/modules/desktop_capture/window_capturer_linux.cc b/modules/desktop_capture/window_capturer_linux.cc
index 2b142ae..89ba90d 100644
--- a/modules/desktop_capture/window_capturer_linux.cc
+++ b/modules/desktop_capture/window_capturer_linux.cc
@@ -34,9 +34,9 @@
 
 #if defined(WEBRTC_USE_X11)
   return WindowCapturerX11::CreateRawWindowCapturer(options);
-#endif  // defined(WEBRTC_USE_X11)
-
+#else
   return nullptr;
+#endif  // defined(WEBRTC_USE_X11)
 }
 
 }  // namespace webrtc