[common] rects: refactor rect buffer copy code to common module

This also fixes a bug of accidentally multiplying the stride by 4 when
the stride is already in bytes and not pixels.

host/platform/Windows/capture/NVFBC/src/nvfbc.c

@@ -26,6 +26,7 @@
 #include "common/option.h"
 #include "common/framebuffer.h"
 #include "common/event.h"
+#include "common/rects.h"
 #include "common/thread.h"
 #include "common/KVMFR.h"
 #include <assert.h>
@@ -482,17 +483,6 @@ static CaptureResult nvfbc_waitFrame(CaptureFrame * frame,
   return CAPTURE_RESULT_OK;
 }
 
-inline static void rectCopyUnaligned(uint8_t * dest, uint8_t * src, int ystart,
-    int yend, int dx, int dstStride, int srcStride, int width)
-{
-  for (int i = ystart; i < yend; ++i)
-  {
-    unsigned int srcOffset = i * srcStride + dx;
-    unsigned int dstOffset = i * dstStride + dx;
-    memcpy(dest + dstOffset, src + srcOffset, width);
-  }
-}
-
 static CaptureResult nvfbc_getFrame(FrameBuffer * frame,
     const unsigned int height, int frameIndex)
 {