Better fix for DAWN_NO_DISCARD on WireResult

The attribute was just in the wrong place, I shouldn't have removed it
completely.

Bug: chromium:1195827
Change-Id: Iad2a5fdcc2e8bd76ddb82cc09cde62c3a57e3c54
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/46800
Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Auto-Submit: Nico Weber <thakis@chromium.org>
Commit-Queue: Austin Eng <enga@chromium.org>
diff --git a/src/dawn_wire/WireResult.h b/src/dawn_wire/WireResult.h
index e6a7691..fc0deb3 100644
--- a/src/dawn_wire/WireResult.h
+++ b/src/dawn_wire/WireResult.h
@@ -19,7 +19,7 @@
 
 namespace dawn_wire {
 
-    enum class WireResult {
+    enum class DAWN_NO_DISCARD WireResult {
         Success,
         FatalError,
     };