BUG: Reset m_Dimension in VideoFileWriter

Identified by:

  D:\a\1\s\Modules\Video\IO\include\itkVideoFileWriter.hxx(256): warning C4834: discarding return value of function with 'nodiscard' attribute

.empty() only returns whether the container is empty or not.

Modules/Video/IO/include/itkVideoFileWriter.hxx

@@ -253,7 +253,7 @@ VideoFileWriter<TInputVideoStream>::InitializeOutputParameters()
   const VideoStreamType * input = this->GetInput();
 
   // Set dimensions
-  m_Dimensions.empty();
+  m_Dimensions.clear();
   typename FrameType::SizeType size = input->GetFrameLargestPossibleSpatialRegion(frameNum).GetSize();
   for (unsigned int i = 0; i < FrameType::ImageDimension; ++i)
   {