Remove ignored return code from modules.

ModuleProcessImpl doesn't act on return codes and having them around is
confusing (it's unclear what an error return code here would do even).

BUG=
R=tommi@webrtc.org

Review URL: https://codereview.webrtc.org/1703833002 .

Cr-Commit-Position: refs/heads/master@{#11747}
diff --git a/webrtc/modules/video_coding/video_coding_impl.cc b/webrtc/modules/video_coding/video_coding_impl.cc
index 7f74b41..7d6d177 100644
--- a/webrtc/modules/video_coding/video_coding_impl.cc
+++ b/webrtc/modules/video_coding/video_coding_impl.cc
@@ -94,12 +94,9 @@
     return VCM_MIN(sender_time, receiver_time);
   }
 
-  int32_t Process() override {
-    int32_t sender_return = sender_.Process();
-    int32_t receiver_return = receiver_.Process();
-    if (sender_return != VCM_OK)
-      return sender_return;
-    return receiver_return;
+  void Process() override {
+    sender_.Process();
+    receiver_.Process();
   }
 
   int32_t RegisterSendCodec(const VideoCodec* sendCodec,