Avoid temporary variable

Author: NicolasHug

src/torchcodec/decoders/_core/VideoDecoder.cpp

@@ -1073,9 +1073,8 @@ VideoDecoder::BatchDecodedOutput VideoDecoder::getFramesInRange(
   BatchDecodedOutput output(numOutputFrames, options, streamMetadata);
 
   for (int64_t i = start, f = 0; i < stop; i += step, ++f) {
-    auto preAllocatedOutputTensor = output.frames[f];
     DecodedOutput singleOut =
-        getFrameAtIndex(streamIndex, i, preAllocatedOutputTensor);
+        getFrameAtIndex(streamIndex, i, output.frames[f]);
     output.ptsSeconds[f] = singleOut.ptsSeconds;
     output.durationSeconds[f] = singleOut.durationSeconds;
   }
@@ -1167,9 +1166,8 @@ VideoDecoder::getFramesDisplayedByTimestampInRange(
   int64_t numFrames = stopFrameIndex - startFrameIndex;
   BatchDecodedOutput output(numFrames, options, streamMetadata);
   for (int64_t i = startFrameIndex, f = 0; i < stopFrameIndex; ++i, ++f) {
-    auto preAllocatedOutputTensor = output.frames[f];
     DecodedOutput singleOut =
-        getFrameAtIndex(streamIndex, i, preAllocatedOutputTensor);
+        getFrameAtIndex(streamIndex, i, output.frames[f]);
     output.ptsSeconds[f] = singleOut.ptsSeconds;
     output.durationSeconds[f] = singleOut.durationSeconds;
   }