Fix -Wunused-but-set-variable.

Bug: None
Change-Id: Idc55e5d4ef522349f0d76f10dd2738408ab994e3
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/236586
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35282}
diff --git a/modules/video_capture/windows/help_functions_ds.cc b/modules/video_capture/windows/help_functions_ds.cc
index ad4c064..58b9de9 100644
--- a/modules/video_capture/windows/help_functions_ds.cc
+++ b/modules/video_capture/windows/help_functions_ds.cc
@@ -60,7 +60,6 @@
 }
 
 IPin* GetOutputPin(IBaseFilter* filter, REFGUID Category) {
-  HRESULT hr;
   IPin* pin = NULL;
   IEnumPins* pPinEnum = NULL;
   filter->EnumPins(&pPinEnum);
@@ -68,7 +67,7 @@
     return NULL;
   }
   // get first unconnected pin
-  hr = pPinEnum->Reset();  // set to first pin
+  pPinEnum->Reset();  // set to first pin
   while (S_OK == pPinEnum->Next(1, &pin, NULL)) {
     PIN_DIRECTION pPinDir;
     pin->QueryDirection(&pPinDir);