Cleanup: modernize-use-equals-default

This was missing from rB19dfb6ea1f6745c0dbc2ce21839c30184b553878.

source/blender/imbuf/intern/dds/ColorBlock.cpp

@@ -46,11 +46,6 @@ inline static uint colorDistance(Color32 c0, Color32 c1)
 }
 #endif
 
-/** Default constructor. */
-ColorBlock::ColorBlock()
-{
-}
-
 /** Init the color block from an array of colors. */
 ColorBlock::ColorBlock(const uint *linearImage)
 {

source/blender/imbuf/intern/dds/ColorBlock.h

@@ -34,7 +34,7 @@
 
 /** Uncompressed 4x4 color block. */
 struct ColorBlock {
-  ColorBlock();
+  ColorBlock() = default;
   ColorBlock(const uint *linearImage);
   ColorBlock(const ColorBlock &block);
   ColorBlock(const Image *img, uint x, uint y);

source/blender/imbuf/intern/dds/DirectDrawSurface.cpp

@@ -890,10 +890,6 @@ DirectDrawSurface::DirectDrawSurface(unsigned char *mem, uint size) : stream(mem
   }
 }
 
-DirectDrawSurface::~DirectDrawSurface()
-{
-}
-
 bool DirectDrawSurface::isValid() const
 {
   if (header.fourcc != FOURCC_DDS || header.size != 124) {

source/blender/imbuf/intern/dds/DirectDrawSurface.h

@@ -136,7 +136,6 @@ struct DDSHeader {
 class DirectDrawSurface {
  public:
   DirectDrawSurface(unsigned char *mem, uint size);
-  ~DirectDrawSurface();
 
   bool isValid() const;
   bool isSupported() const;