Remove more unnecessary Clear's

Author: brianpopow

src/ImageSharp/Formats/Webp/Lossy/QuantEnc.cs

@@ -340,8 +340,6 @@ public static int ReconstructIntra4(Vp8EncIterator it, Vp8SegmentInfo dqm, Span<
             Span<byte> reference = it.YuvP.AsSpan(Vp8Encoding.Vp8I4ModeOffsets[mode]);
             Span<short> tmp = it.Scratch2.AsSpan(0, 16);
             Span<int> scratch = it.Scratch3.AsSpan(0, 16);
-            tmp.Clear();
-            scratch.Clear();
             Vp8Encoding.FTransform(src, reference, tmp, scratch);
             int nz = QuantizeBlock(tmp, levels, ref dqm.Y1);
             Vp8Encoding.ITransform(reference, tmp, yuvOut, false, scratch);
@@ -357,8 +355,6 @@ public static int ReconstructUv(Vp8EncIterator it, Vp8SegmentInfo dqm, Vp8ModeSc
             int n;
             Span<short> tmp = it.Scratch2.AsSpan(0, 8 * 16);
             Span<int> scratch = it.Scratch3.AsSpan(0, 16);
-            tmp.Clear();
-            scratch.Clear();
 
             for (n = 0; n < 8; n += 2)
             {

src/ImageSharp/Formats/Webp/Lossy/Vp8Encoding.cs

@@ -81,7 +81,6 @@ public static void ITransformOne(Span<byte> reference, Span<short> input, Span<b
         {
             int i;
             Span<int> tmp = scratch.Slice(0, 16);
-            tmp.Clear();
             for (i = 0; i < 4; i++)
             {
                 // vertical pass.
@@ -124,7 +123,6 @@ public static void FTransform(Span<byte> src, Span<byte> reference, Span<short>
         {
             int i;
             Span<int> tmp = scratch.Slice(0, 16);
-            tmp.Clear();
 
             int srcIdx = 0;
             int refIdx = 0;
@@ -163,7 +161,6 @@ public static void FTransform(Span<byte> src, Span<byte> reference, Span<short>
         public static void FTransformWht(Span<short> input, Span<short> output, Span<int> scratch)
         {
             Span<int> tmp = scratch.Slice(0, 16);
-            tmp.Clear();
 
             int i;
             int inputIdx = 0;